Preheat the oven to 400℉. Prepare muffin tins with 18 muffin liners or spray with non-stick cooking spray.

In a large mixing bowl, whisk together the melted butter, oil, sugar, and brown sugar until combined. Add the eggs and vanilla and continue whisking. Add the sour cream and milk and whisk just until fully incorporated and smooth.

In another bowl, whisk together the flour, baking powder, salt, frozen raspberries, and white chocolate chips. Add to the wet ingredients and gently fold together just until no clumps of unmixed flour remain. Do not overmix or the raspberries will bleed into the batter!

Divide the batter evenly between all 18 prepared muffin liners. Bake in the 400℉ preheated oven for 5 minutes. Then, turn the oven down to 350℉ and bake for an additional 15-20 minutes or until a toothpick inserted into the center comes out dry. Let cool in the pan for 10 minutes before transferring to a wire rack to finish cooling. Enjoy!