In a large bowl, beat together the cake mix, vegetable oil, eggs and vanilla extract for 2 minutes until well combined and fluffy.
Pour the batter into the prepared baking dish.
Press the raspberries into the batter, then use a spatula to even out the top of the batter and slightly cover the majority of the raspberries.
Bake for 20-24 minutes until an inserted toothpick comes out clean.
Allow the blondies to cool completely before preparing the glaze.
In a small bowl, whisk together all glaze ingredients.
Pour the glaze all over the blondies and smooth over with an offset spatula until blondies are completely covered.
Allow the glaze to set for at least 1 hour before cutting the blondies to store or serve.
Christina's Notes
Raspberry Jam: Don't have any fresh or frozen raspberries? No problem, just use raspberry jam or jelly. You can add gobs it the top and use a knife to swirl into the blondies.
Other Berries: You can absolutely switch in any other berries such as blueberries, blackberries, or strawberries.
White Chocolate Chips: For some extra creamy and richness, fold in white chocolate chips to batter.