Preheat oven to 375°F (190°C). Grease a 12-cup popover pan or muffin tin with cooking spray.
In a large bowl, whisk together the flour, baking powder, and salt. Set aside.
In a medium bowl, whisk together the melted butter, milk, eggs, and vanilla extract. Add the wet ingredients to the dry ingredients and stir until just combined.
Stir in the white sugar, brown sugar, pecans, and raisins. Divide the batter evenly among the prepared muffin cups.
Bake for 25 to 30 minutes, or until the popovers are golden brown and a toothpick inserted into the center comes out clean.
Remove from oven and let cool for 10 minutes before serving.
Interesting Facts
Popovers are a type of pastry that originated in England and are made with a light batter that is then baked in a hot oven.
Popovers are usually made in a special popover pan or muffin tin, which has deeper cups than a regular muffin tin.
Popovers are best served warm and are usually served with butter and jam.