Whisk your dry ingredients (white boxed cake mix, box of white chocolate pudding) together in a medium-sized mixing bowl.
In a large bowl, whisk together the eggs, buttermilk, sour cream, oil, and vanilla. Add the dry ingredients to the wet ingredients and mix together until combined. Add the melted white chocolate at the end and mix it into the mixture.
Place the fresh raspberries in a separate bowl. Coat them with 1 tablespoon of flour. Remove the raspberries, leaving the excess flour in the bowl. Fold in the flour-coated raspberries and the white chocolate chips into the cake batter by hand.
In a greased and floured bundt pan, pour half of the cake batter. Add your raspberry filling in a circle on top of the batter. Take a toothpick and gently swirl the jam into the cake mixture.
Pour the rest of the batter into the bundt cake pan and smooth it out. Bake in the oven at 350F for 40-45 minutes, or until a knife comes out clean.