In a food processor or mixing bowl, whip the mascarpone cheese and confectioner's sugar until smooth and creamy. Add eggs, one at a time, beating just until blended after each addition.
Beat in the espresso. The mixture should be creamy and easy to spread at this point. If not, add a bit more espresso.
Spread a thick layer of Tiramisu filling over the pre-baked pizza dough.
Dust the cheese liberally with cocoa powder, followed by a very light dusting of confectioner's sugar to achieve a dappled effect.
Fresh fruit can be arranged around the edge of the pizza as a garnish.