Chocolate-Pecan Nut Slices
Preheat the oven to 180°C (approximately 350°F). Line a baking sheet with parchment paper. Place the flour in the bowl of an electric mixer fitted with the dough hook. Add 100 grams of the butter cut into small pieces, the sugar, cocoa powder, salt, egg yolk and 2 tablespoons of espresso and knead to a smooth dough. Place the dough between 2 sheets of lightly floured plastic wrap and roll the dough to a rectangle 18 x 20 cm (approximately 7 x 8-inches) and about 0.5 cm (approximately 1/4-inch) thick. Roll out and place on the baking sheet. Bake 12-16 minutes and let cool on the sheet.
For the topping, coarsely chop the chocolate. Heat the cream in a saucepan, remove from the heat and add the chocolate to the pan. Cover and let stand until the chocolate has melted, about 3 minutes. Stir in 15 grams (approximately 1 tablespoon) of the butter and the remaining espresso (2 tablespoons). Cover and let stand until cool and of a spreading consistency, about 30 minutes. Spread the chocolate over the cooled pastry. Coarsely chop the pecans and sprinkle them over the top. Let stand until the chocolate has firmed up, about 30 minutes. Cut into 3 x 5 cm (approximately 1 x 2-inch) pieces.