Preheat the oven to 400°F. Line a muffin tray with muffin liners and set aside.
In a small bowl, whisk together the flour, baking powder and salt. Set aside.
Beat together the oil, white sugar, and ricotta cheese until light and fluffy, about 2 minutes.
Add the eggs and vanilla extract and beat until combined.
Stir in the flour mixture until combined and no dry streaks remain, then stir in the milk until completely incorporated. Do not overmix.
Stir in the white chocolate chips.
Toss the raspberries in the reserved flour to coat completely, then gently fold into the muffin batter.
Portion out the muffin batter into the prepared muffin liners, up to ¾ full.
Bake for 22-25 minutes or until a toothpick inserted in the center comes out clean and muffins are golden.