Cream together the butter and sugar in the bowl of an electric mixer fitted with the paddle attachment on medium speed until fluffy and pale, scraping the sides of the bowl as necessary.
Add the vanilla extract and continue mixing until incorporated.
Add the flour to the butter mixture and mix on low until a cohesive dough forms.
Add the chocolate chips and stir until uniformly distributed.
Press 1/4 cup of dough into each tartlette well, beginning from the center, so that it rises up the wall. Continue until a shell of uniform thickness and height is formed around the entire wall. Repeat with the remaining wells.
Place the pan on a rimmed cookie sheet and bake for 20 minutes or until golden brown.
Allow to cool on the cookie sheet on a cooling rack.
5-Minute Cannoli Filling
Combine the ricotta and mascarpone cheeses, orange zest, and vanilla.
Add the powdered sugar and stir until smooth and creamy.
Cover with plastic wrap and chill in the refrigerator for about two hours until it is set**.
Fill the tartlettes and garnish by grating the dark chocolate bar using a zester over each tartlette.
Notes
*If using unsalted butter, add a pinch of salt to the flour**It will thicken and resemble a pudding-like consistency