Domenico's Chocolate Cannoli

Source: Domenico's on Fisherman's Wharf - Monterey, California - Courtesy of Bon Appetit, October, 1987

Filling
1 pound ricotta, drained if necessary
1 cup powdered sugar
1/2 cup walnuts, toasted and chopped
1/3 cup semisweet chocolate chips
1 teaspoon grated orange peel
1/2 teaspoon grated lime peel

Dough
1 cup all-purpose flour
1 teaspoon baking powder
1 teaspoon powdered sugar
Pinch salt
1/3 cup beer
1 tablespoon unsalted butter at room temperature
1 egg, beaten to blend
1 teaspoon vanilla extract
Vegetable oil for deep frying

For filling: Pur