Preheat the oven to 350 degrees and coat a 10-12 cup Bundt pan with baking spray (with flour added). Make sure to coat the whole pan and use a pastry brush to brush any missed spots. Don’t allow excess spray to pool at the bottom of the pan.
In a small bowl, combine 1 tablespoon of flour with the white chocolate chips and raspberries and stir gently until everything is coated in flour. Set aside.
In a medium bowl, combine flour, baking powder, and salt. Set aside.
In a stand mixer or in a large bowl and a hand mixer, cream together butter and sugar for about 3-4 minutes, until light yellow and fluffy on medium/medium-high speed.
Add eggs, one at a time, mixing well and scraping the sides of the bowl after each addition.
In a small bowl or pourable measuring cup, whisk together sour cream, milk and vanilla. Set aside.
Starting with the dry ingredients, add about ⅓ to the butter/sugar mixture and beat until combined.
Add half of the milk/sour cream mixture and mix well. Continue alternating dry and wet ingredients, ending with the dry ingredients and stirring until just a few streaks of flour remain.
Fold in the white chocolate chips and the raspberries gently, being careful to not break up the raspberries while mixing.
Pour the batter into the prepared bundt pan and smooth the top. Bake for 45-50 minutes until a toothpick comes out clean or with a few moist crumbs.
Cool for 10-15 minutes in the pan and then invert the pan onto the serving platter you will be using and let it cool completely.