3cups(about 454-481g)fresh or frozen blueberries (don't thaw if using frozen)
16ounces(454g)vanilla cake mix, homemade version below
9tablespoonsbutter, chilled
½cupbuttermilk or milk, chilled
Ice cream or whipped cream, for serving
Easy Homemade Cake Mix:
1cup(212g)granulated sugar
¾cup(107g)all-purpose flour
⅔cup(76g)cake flour (see note)
¼cup(35g)nonfat dry milk powder
½tablespoonbaking powder
½teaspoonsalt
1tablespoonvanilla extract
Instructions
Preheat the oven to 325 degrees F. Lightly grease a 9X12- or 9X9-inch baking dish with cooking spray. The cake will obviously bake up thicker if using a 9X9-inch baking pan.
Add the blueberries to the pan in an even layer. Set aside.
If making the homemade cake mix, whisk together all the dry ingredients and sift through a fine mesh strainer into a bowl. Reserve the vanilla to use later with the buttermilk (or milk).
Using a cheese grater (as pictured in the post), grate the chilled butter into the dry cake mix. Using your hands, toss the cake mix and butter together until the butter is uniformly distributed and the mixture looks like coarse sand. Make sure not to go crazy here - you don't want to melt the butter as you toss it all together.
Dump the cake/butter mixture onto the blueberries and toss with your hands to combine.
Whisk together the buttermilk (or milk) and vanilla (only need to do this if using the homemade cake mix recipe above). Drizzle the mixture in a thin stream over the top of the cake.
Bake the cake until the batter is puffy and lightly golden, about 35-38 minutes for a 9X12-inch pan and a few minutes longer for a 9X9-inch pan. Don't overbake or the bottom may burn.
Serve warm or at room temperature (let's be honest, warm is the way to go) with a scoop of ice cream or a dollop of whipped cream.
Notes
For the Homemade Cake Mix: since I never have cake flour on hand and always make my own cake flour, I either measure about 1/2 cup all-purpose flour + 2 tablespoons cornstarch for the 2/3 cup cake flour in the recipe, OR I weigh the amounts (3 ounces all-purpose flour and about .5 ounce cornstarch). Flour: if you are already weighing out the all-purpose flour also, you can simplify and for the entire homemade cake mix, you can weigh 6.25 ounces total all-purpose flour and .5 ounce cornstarch. Make sense?