A chocolate tart is a French pastry classic. It is simple, elegant and rich. There are lots of personal variations, but the traditional version is often a chocolate sweet dough crust with a dark chocolate ganache or custard and a nougatine (a mixture of hard caramel and nuts) top.
We’re going to make my personal variation today (go figure). We will add a layer of chocolate cake to the tart and use a milk chocolate custard to keep it a little lighter in chocolate flavor. Instead of a nougatine, we’ll make a pretty chocolate decoration for the top, but still keep everything looking sleek and simple.
If you plan to skip the chocolate decoration, the only special equipment you’ll need is a tart ring. If you do want to make the decoration (good for you!) see the list of equipment needed listed out like ingredients under the decoration section of the recipe (see the recipe notes on where to get a few of the items).
The cake we’re making is a variety known as a biscuit (say: “bis-quee”), which is a sponge cake made mostly of whipped egg yolks and meringue folded together. If I’m being honest, the traditional French recipe(s) for biscuit are often pretty bad by themselves, intentionally dry and bitter so as to be well balanced with sweeter components. That’s all well and good, but we’ll try my recipe, which I think is pretty tasty on it’s own.
The biscuit recipe involves to whipped components – the egg yolks and the egg whites. The best way to make the recipe is to start with the egg yolks mixture, as it will hold it’s volume longer than the meringue. If you’re using one mixing bowl, be sure to clean it thoroughly with soap and water before whipping the meringue. Any remaining fat in the bowl from the egg yolks can prevent the meringue from developing.
Lastly, you’ll see the recipe call for inverted sugar. This isn’t 100% necessary to make the cake, but does help add moistness and shelf life to the cake in a professional application. The industry standard to use is a product called Trimoline, but this comes in a rather large quantity. Corn syrup and honey are two inverted sugars you can use as an alternative, just keep in mind the honey will add honey flavor to your cake.
As always, before tackling this decoration you should have a good understanding of how to temper chocolate. The equipment notes below come from a previous post on chocolate decoration that has some good info in it about the general process.
acetate sheets – acetate sheets come in various sizes and thicknesses. They are the premier surface to cast chocolate on because they are flexible and easy to move, and will give your chocolate a nice shine. You can get these at art supply stores or of course the webernet.
plexiglass sheets – thick sheets of acrylic, I use plexiglass in my work kitchen because they are nice and flat and don’t bend and flex like a metal sheet pan can. ¼”/.6cm sheets are ideal since anything thicker is too expensive and anything thinner will flex on you when you try to move it, which can crack or ruin your decoration. These sheets can actually be found in home improvement stores and usually in convenient 18×24”/46x61cm sheets. That size is a bit large for a home kitchen, but cut into two 18×12”/46x30cm piece will work for most needs.
A dull paring knife is called for in the equipment list for the decoration. I have a very dull knife I use for all of my chocolate work since it won’t scratch plexiglass but is still sharp enough to cut through chocolate. You can purchase a cheap paring knife at a culinary store and just beat it up to make your own. If you only have a sharp paring knife that’s fine, just be very gentle when cutting your chocolate decoration.
chocolate sweet dough
90g butter unsalted
110g whole eggs
310g pastry flour
50g cocoa powder Guittard Cocoa Rouge cocoa powder
*1 egg white for brushing your baked tart shell
Bring the butter and the whole eggs to room temp. before getting started.
Combine the pastry flour, salt and cocoa powder and sift. Reserve to use later.
Combine the butter and sugar in a stand mixer with a paddle attachment and cream them.
Add the whole eggs to the butter mixture and mix until fully emulsified. The mixture should look shiny.
Add the sifted dry ingredients and mix until just bound.
Press the soft dough into a shape that will be easy to roll later and wrap it tightly in plastic.
Chill the dough in the refrigerator for a min. of 1hr. up to overnight.
Roll the dough out to 1/8”/3mm and line your tart ring. Check out my recipe for a cherry tart for some pointers on how to line your ring.
Dock the bottom of the shell and bake at 350F/176C for 8-10min.
While the tart shell is baking, whisk your egg white to smooth it out.
Remove the baked shell and immediately brush it with a thin layer of the egg white, then place the shell back in the oven for 1-2min. The egg will help seal any holes in the shell from docking and keep the shell from getting soggy once you add the custard.
Reserve the baked shell at room temperature for final assembly.
80g cake flour
37g cocoa powder Guittard Cocoa Rouge cocoa powder
10g chocolate, 70% Guittard Complexite
60g butter unsalted
230g egg yolks
150g sugar A
40g inverted sugar
190g egg whites
30g sugar B
Combine the cake flour, cocoa powder and salt and sift. Reserve them to use later.
Combine and melt the butter and chocolate. This can be done over a double boiler or slowly in the microwave. If you use the microwave, begin with the chocolate and once it has started to melt, add the butter.
Combine the egg yolks, sugar A, and inverted sugar in a stand mixer with a whip attachment.
Whisk the mixture on medium speed for approx.. 6-8min. until it is light and thickened and falls off the whisk in a smooth stream.
Combine the egg whites and half of the sugar B in a stand mixer with a whip attachment and whisk the egg whites on medium speed until the are frothy and no clear albumen is still intact.
Add the remaining sugar to the meringue and whisk on high speed until the meringue just reaches stiff peaks.
Fold the melted chocolate mixture into the whipped egg yolks.
Fold the sifted dry ingredients into the batter.
Fold the meringue into the batter in two stages.
Cast the batter into a prepared cake ring or mold and bake at 360F/182C for 8-10min.
Let the cake cool and cut into ¼”/6mm thick slice. Reserve the sliced cake, wrapped and in the cooler, for final assembly.
milk chocolate custard
140g heavy cream
140g whole milk
60g egg yolks
266g chocolate, 45% Guittard Soleil d’Automne
Hydrate the gelatin in cold water for a minimum of five minutes and reserve.
Combine the heavy cream and whole milk in a sauce pot and bring it to a simmer over medium heat.
While the cream mixture is heating, combine the sugar and egg yolks, whisking well to incorporate the two.
Temper the hot cream mixture into the yolks, adding 2-3 small additions and whisking well with each addition. Pour the tempered yolks back into the sauce pot with the remaining cream and milk.
Return the sauce pot back to the stove and cook the mixture, whisking constantly, until it reaches 185F/85C.
Squeeze out the excess water from the gelatin and add it to the custard base.
Add the chocolate and whisk or hand blend the mixture until smooth and homogenized.
1 x 18×12”/46x30cm plexiglass sheet
1 x 18×12”/46x30cm acetate sheet
1 x offset spatula
1 x dull paring knife (a sharp one will work too, just be gentle)
1 x 8”/20cm ring or circular template
1 x dough scraper
1 x parchment paper
1 x heavy book, sheet pans or a second piece of plexiglass
Before getting started, sprinkle a light amount of water onto your plexiglass sheet and spread it around with your hand.
Gently lay the acetate onto the plexiglass and using a dough scraper, press the water out to the edges to create a seal between the two. Dry the surfaces thoroughly.
Temper your milk chocolate and pour some onto the acetate.
Using the offset spatula, spread the chocolate in a thin, even layer over the acetate, large enough to cut a circle into.
Let the chocolate set until it loses its glossy sheen and if you gently place your finger tip onto the surface, the chocolate doesn’t stick.
Place the circular template onto the chocolate and lightly trace the shape with your paring knife.
Cut lines from the outside of your circle through the excess chocolate. This will make it easy to remove the chocolate around your single when everything is set.
Remove the template and cut a geometric pattern into the circle. Keep in mind the side of the chocolate facing down and touching the acetate will be facing up in the final product.
Place a piece of parchment paper or acetate over the chocolate.
Place a heavy book, sheet pans or a second piece of plexiglass over the chocolate disk and let it set fully.
Pour a small quantity of the milk chocolate custard into the bottom of the tart shell, spreading it evenly.
Place the slice of biscuit onto the custard, pressing gently to adhere it.
Pour the milk chocolate custard over the slice of biscuit until it is nearly flush with the top of the tart shell.
Place the tart in the refrigerator for 1-2hr. to set.
Gently remove the cut pieces of milk chocolate decoration from the sheet of acetate and rearrange them on top of your tart with the shiny side facing up.