In a mixing bowl, combine gluten-free flour, sugar, xanthan gum, baking powder, and salt.
Add cold, cubed butter and mix until the mixture resembles coarse crumbs.
Stir in beaten egg and white wine (or water) until the dough comes together.
Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.
Roll out the dough on a floured surface and cut into circles.
Wrap the circles around cannoli forms and fry in hot oil until golden brown. Remove and let cool.
For the filling, mix ricotta cheese, powdered sugar, and vanilla extract until smooth. Fold in mini chocolate chips if using.
Fill the cooled cannoli shells with the ricotta mixture using a piping bag.
Serve immediately or refrigerate until ready to serve.