Preheat oven to 400°F. Grease or line a standard 12-cup muffin tin with paper liners and set it aside.
In a small bowl, whisk together flour, baking powder, and kosher salt. Set aside.
2 cup (240 grams) all-purpose flour, 1 tablespoon baking powder, ½ teaspoon kosher salt
In a large bowl, use a hand mixer to cream together butter and sugar until the mixture is light and fluffy. Add oil and eggs to the butter-sugar mixture. Beat until smooth and well-blended. Mix in milk and vanilla extract until well combined. Don't worry if the mixture looks curdled; it's just the butter solidifying from the cold milk.
4 tablespoons (½ stick) unsalted butter, ½ cup granulated sugar, ¼ cup canola oil, 2 large eggs, 1 cup milk, 1 teaspoon vanilla extract
Gently fold the dry ingredients into the wet ingredients until just combined. Be careful not to overmix. Fold in raspberries and white chocolate chips until evenly distributed in the batter.
1 cup raspberries, ½ cup white chocolate chips
Divide the batter evenly among the 12 muffin tin wells. If desired, top each muffin with extra raspberries and white chocolate chips.
Extra raspberries and white chocolate chips
Bake for 20-25 minutes or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely before storing.