In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt.,In a separate bowl, beat together the sugar, eggs, oil (or melted butter), vanilla extract, and raspberry extract or jam until smooth.,Add the dry ingredients to the wet ingredients and stir until a thick dough forms.,Cover and chill the dough in the refrigerator for at least 1–2 hours (or overnight).,Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.,Scoop tablespoon-sized portions of dough and roll into 1-inch balls.,Roll each dough ball generously in powdered sugar to coat.,Place on the baking sheet about 2 inches apart and bake for 10–12 minutes, until the tops are cracked and edges are set.,Cool on the baking sheet for a few minutes, then transfer to a wire rack to cool completely.