Typically this marvelous tart is made in a 10″ springform pan, but as you can see, it makes a perfect Valentine’s Day dessert when made into a heart. Either way, it is devine.
For the base:
28 Oreo cookies
2 oz. bittersweet chocolate (preferably at least 70% cocoa solids)
3 tbs. butter, softened
1/2 tsp. smoked sea salt flakes (Maldon makes a wonderful one)
For the filling:
4 oz. bittersweet chocolate (preferably at least 70% cocoa solids)
3 tbs. cornstarch
1/4 cup whole milk
2 cups heavy cream
7 tbs. unsweetened cocoa powder, sifted
2 tsp. instant espresso powder or strong instant coffee powder
1/3 cup sugar
1 tsp. vanilla extract or paste
2 tsp. extra-virgin olive oil
3/4 tsp. smoked sea salt flakes
Snap the cookies into pieces and drop into the bowl of a food processor. Do likewise with the chocolate and whizz into crumbs. Add the butter and salt and blitz until everything clumps together. (To do this by hand, bash the cookies with a rolling pin in a sealed plastic bag, finely chop the chocolate and melt the butter. Stir everything together in a bowl.) Tip into a 10″ springform pan, pushing it with a wooden spoon into the bottom and up the sides. Chill and harden at least 1 hour, but not more than a day.
For the filling, finally chop the chocolate. Put the cornstarch into a cup and whisk in the milk until smooth. Pour the cream into a heavy saucepan into which all the ingredients can fit. Add the chopped chocolate, cocoa, espresso powder, sugar, vanilla, olive oil and sea salt flakes. Place over a medium heat and whisk until melted and smooth.
Off the heat, whisk in the cornstarch mixture until fully incorporated. Put it back on a low heat and mix with a wooden spoon until thickened, about 10 minutes. Do not let it boil. When ready, it should be thick enough to coat the back of the spoon, and if you run your finger through it, the line should stay. Pour into a large measuring cup. Take a piece of parchment paper and run it under the cold tap. Wring it out, scrunch it up and place it over the chocolate. Chill for 15 minutes.
Smooth the chocolate in the base, cover and chill overnight. Remove 10 minutes before serving and untold, living the base pan on.