Place the raspberries in the freezer while you prep the rest of your ingredients. Line an 8x8 inch baking dish with parchment paper or foil, and spray with cooking spray.

In a small bowl, add the flour, baking powder, and salt. Give it a whisk to combine and set aside.

Melt the butter until just melted but not too hot and set aside.

Add the brown sugar and white sugar to a medium sized bowl. Pour the melted butter over the sugars and whisk until combined, about 30-60 seconds.

Add in the egg and the vanilla and mix until well combined and glossy, about 45-60 seconds. This is what gives you the shiny top after baking!

Add the dry ingredients to the wet ingredients and mix until almost fully combined, but streaks of flour are still showing.

Pour in the white chocolate and the frozen raspberries. Gently fold the batter until the chips and berries are just combined and no streaks of flour remain.

Scoop the batter into the prepared baking dish and gently press the blondie dough out to the edges. Make sure to distribute clumps of raspberries to areas that don’t have any berries. This will help the blondies bake more evenly.

Bake at 350 degrees F for 25-30 minutes until a toothpick inserted comes out with fudgy crumbs (not clean) and the top is puffed and shiny. Do not overbake.

Let cool for 2 hours before slicing, the center should be gooey and fudgy but set.