In a large bowl, mix the flour, baking powder and baking soda.
In a separate bowl mix the sugar, oil, sour cream, egg, egg yolk, and vanilla extract. Set aside for ten minutes stirring every few minutes.
Pour the wet ingredients over the flour mixture and use a rubber spatula to mix.
Midway through mixing in the dry ingredients, add the raspberries and white chocolate and continue mixing. Only mix until the flour has been hydrated, do not overmix.
Allow the batter to rest for 20-60 minutes. (or up to 4 hours)
Preheat oven to 350F (180C).
Line a muffin pan with muffin liners, fill each slightly over the top, and bake for 23-25 minutes, or until a toothpick comes out dry from the center of the muffins and the tops are golden brown.
Remove from the oven, allow to chill for about 5 minutes, and serve.