Add all the ingredients to a blender and blend until a smooth, well-combined batter forms.
Let the batter rest for 5 minutes, so any air bubbles that formed during blending can escape.
Heat a medium amount of butter in a 24 centimeter non-stick skillet over medium heat. Swirl the pan around to coat it evenly with the butter.
Once the butter is hot and begins to sizzle, add a few spoonfuls of batter to the pan and swirl it around to form a thin, even layer that reaches almost to the edges of the skillet. Cook the crêpe until the edges are set and can be lifted with a spatula. Once the edges look cooked, gently loosen the crêpe all around the edge with the spatula. Then, lift up one edge of the crêpe and slide the spatula underneath to flip it over. Gently flip the crêpe and continue cooking the other side until it is lightly golden brown on both sides. Once both sides are cooked to your liking, remove the crêpe from the pan and place it on a plate.
Repeat this process with any remaining batter, and then stack the crêpes with parchment paper between layers to prevent sticking.
You will get between 10 to 12 thin crêpes. Allow them to cool completely before assembling the cake.
Make the Mascarpone Cream
In a large bowl, whip the cream and sugar into stiff peaks. Add the mascarpone cheese and stir it in with a spatula until smooth and creamy.
Assemble the Cake
Set aside about 1/5 of the mascarpone cream for decorating and start creating the layers.
Place a crepe on a cake plate and cover it with a thin layer of cream, spreading it to the edges. Repeat this process until you use up all the crepes and cream, finishing with a crepe. Refrigerate for at least 1 hour to firm up both the cake and decorating cream.
Take the remaining cream and put it in a pastry bag. Pipe puffs of cream all over the top of the cake. If you don’t want to use a pastry bag, you can spread a thick, even layer of cream and then draw continuous waves across using two toothpicks.
Allow your Tiramisu Crepes Cake to chill in the refrigerator, covered, for at least two hours before serving.
Right before serving, dust the top with powdered unsweetened cocoa.