Prepare the Dough

1. Warm 2 cups of milk in a large pan but do not bring to a boil.
2. Gradually whisk in 3/4 cup semolina flour until smooth.
3. Cook over medium heat, stirring constantly, for about 5 minutes until thickened.
4. Remove from heat and allow to cool.

Combine Ingredients

1. In the cooled mixture, mix in eggs, granulated sugar, all-purpose flour, baking powder, and a pinch of salt until smooth.
2. Stir in the orange zest and let the batter rest for 30 minutes.

Make the Custard Cream

1. Combine 1 cup milk, 1/4 cup heavy cream, and vanilla extract in a pan and bring to a simmer.
2. In a separate bowl, whisk egg yolks, sugar, and cornstarch.
3. Slowly incorporate hot milk into the egg mixture, then return to heat, stirring until thickened.
4. Cool completely and refrigerate.

Fry the Frittelle

1. Heat oil in a deep pan (no more than half full).
2. Drop spoonfuls of batter into the hot oil and fry until golden.
3. Drain on paper towels and let cool.

Assemble

1. Optional: Whip additional heavy cream and fold into custard for a lighter, fluffier filling.
2. Make a hole in one side of the frittelle and fill with custard cream.
3. Dust with powdered sugar before serving.