1. Add the butter and sugar to a large bowl and mix first slowly, then on high speed until light and fluffy. Add the egg and vanilla extract and mix until well combined. Mix the flour with cocoa powder, baking powder, and salt in a smaller bowl and then sift into the bowl with the butter/sugar – mix until just combined. Shape the dough into a ball and place it in the fridge for about 30 minutes.

2. Preheat the oven to 180°C (350°F). Draw the number you want to make on a piece of cardboard or paper and cut it out. Take about 1/2 of the dough and roll it out on a piece of baking parchment to a thickness of about 0,5cm. This works best with a second sheet of baking parchment on top. Place your number on the dough and cut it out. Remove the dough around it and transfer the number with the baking parchment on a baking sheet or wooden board and place that in the fridge for about 20 minutes. Cooling the dough helps it to keep the shape. You can bake without freezing it, but then the dough will spread more. Bake the cake layer for about 10-12 minutes until firm. Take it out of the oven, remove it with the baking parchment from the baking sheet and let it cool down on a wire rack. Repeat with the remaining dough. With the third layer you might have to be a bit creative and do some patchwork to get a full number. With my »5« I had enough dough to also cut out some stars at the end for the decoration.

3. For the Oreo cream separate the filling from the cookies and place it in a small microwave-safe bowl. Add the cookies to a freezer bag and crush with a rolling pin to get fine crumbs. Set aside. Microwave the cream filling in several steps until melted. Set aside. Add the cold heavy cream to a large bowl and whisk until thick and creamy. Add the melted filling of the Oreos, the confectioners‘ sugar, and cream stiffener and whisk until stiff peaks form. Fold in the crushed Oreo cookies – try not to deflate the whipped cream. Fill into a piping bag with a large round tip and place in the fridge until needed.

4. For the whipped cream add the cold heavy cream to a large bowl and whisk until thick and creamy. Mix the confectioners‘ sugar with the stiffener and then add it together with the vanilla extract to the bowl and mix until stiff peaks form. Fill into a piping bag with a large round tip or star tip. Set aside.

5. To assemble the cake, place the first number cookie layer on a serving plate. Pipe the two creams alternating on top of the number to cover it completely – don’t be shy with the cream, you have a lot. If you like, you can sprinkle with some chocolate shavings or sprinkles. Place the second number cookie on top of the cream and press lightly down to connect them. Repeat the piping, then add the last layer and pipe the creams on top as well. Before decorating I recommend to place the cake in the fridge for at least 4 hours or overnight. When ready to serve, decorate the top with your favorite sprinkles, macarons, chocolate candy, pieces of Oreos etc.