Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a large bowl, whisk together flour, baking powder, and salt.

In a separate bowl, cream together the softened butter and granulated sugar until light and fluffy. Beat in the eggs one at a time, then stir in vanilla extract.

Gradually mix the dry ingredients into the wet mixture alternately with the milk, starting and ending with the dry ingredients.

Divide the batter evenly between the prepared pans and smooth the tops.

Bake for 25 minutes or until a toothpick inserted into the center comes out clean.

Allow cakes to cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

For the filling, mix together the ricotta cheese, mascarpone cheese, powdered sugar, and orange zest until smooth. Fold in the mini chocolate chips.

Once the cakes are cool, place one cake layer on a serving plate and spread half of the filling over the top. Add the second cake layer and spread the remaining filling on top.

Chill the cake in the refrigerator for at least 30 minutes before serving to set the filling.