1. In a large bowl, combine flour, baking powder, ricotta, melted butter and salt. Mix until smooth. Cover with plastic wrap and refrigerate for 1 1/2 hours.
2. Divide the dough into 18 equal pieces. Roll each piece into ball.
3. Gently flatten the dough balls with your palm to about 5 inch circles
4. Take one dough circle. Dip it in sugar, then fold over into a half circle (sugar should be inside).
5. Dip in sugar again and fold in half to form a triangle. Dip triangle in sugar. Repeat the process with the rest of the dough.
6. Preheat oven to 380 degrees F (190 degrees C).
7. Place the ricotta triangles on a baking sheet, previously covered with parchment paper. Use 2 baking sheets if necessary. Leave some space between triangles, as they will grow in size.
8. Bake in the preheated oven for 30 minutes, or until lightly browned.