Torta Mimosa

Cool the cakes to room temperature.

Trim the crusts on one of the cakes so there are no dark parts showing. Carefully slice the cake in half horizontally so you have two layers. Set them aside. Trim the top and side crusts of the second cake, leaving the bottom dark. Carefully slice the cake in half horizontally. Set aside the bottom layer. Slice the remaining layer into 1/4-inch-wide (6-millimeter-wide) strips, then cut the strips into cubes. Set the cubes aside.

Put the sugar and 1/2 cup (4 fluid ounces/120 milliliters) water in a small saucepan and bring to a boil. Remove from the heat and stir in the liqueur. Let cool to room temperature.

Put the bottom cake layer on a serving plate. Moisten with one third of the liqueur syrup, then spread with a little less than one third of the pastry cream. Repeat with the next two layers, then spread the remaining pastry cream on the sides of the cake. Press the cake cubes onto the top and sides of the cake. Loosely cover with plastic wrap and refrigerate until set, about 2 hours. Serve cold. Leftovers can be refrigerated for up to 5 days or frozen for at least 6 weeks.