Preheat oven to 400°F with a rack placed in the center of the oven. Grease a 12-count muffin tin.
In a medium bowl, whisk flour, baking powder, baking soda, and salt. Set aside.
In a large bowl using an electric mixer, beat butter and sugar for several minutes, until creamy. Add eggs, one at a time, scraping the sides and bottom of the bowl as needed. Add extracts and sour cream and beat until well combined (it might look a little curdled. That's OK).
Add half the dry ingredients, beating until just combined. Then add the milk, beating until just combined. Beat in the remaining dry ingredients. Using a wooden spoon or rubber spatula gently stir in raspberries and white chocolate chips.
Scoop the batter into the prepared muffin cups (it will be thick). I like to dampen my finger and smooth the top of each muffin. Place the muffin tin in the oven and immediately turn down the temperature to 375°F. Bake for 15-20 minutes, until a toothpick inserted into the center comes out clean. If desired, you can rotate the pan once during bake time to ensure even browning. Place the pan on a wire rack to cool for 10 minutes, then remove the muffins and place on the rack to cool completely.
Vanilla icing:
Whisk all ingredients until smooth and creamy. If necessary, add more milk to thin or powdered sugar to thicken. Drizzle the top of each muffin.
Notes
*Fluff the four with your measuring cup, scoop a heaping portion, and level it off with the back of a knife. SERVING & STORAGE: These muffins are the best the day they are made. Leftovers can be stored tightly covered in the refrigerator for up to 3 days. Reheat before serving. I like to split the muffins and place in a 375°F oven for about 5 minutes.