To prepare a yummy blueberry breakfast cake recipe, preheat the oven to 350 degrees F (180 degrees C). Grease and flour two 8-inch round pans and set aside. Sift the flour, baking powder, sugar and salt into the bowl of an electric mixer and mix until the ingredients are well-combined. Add the blueberries and beat the mixture on medium-high speed until it's light and fluffy, about 5 minutes. Fold in the vanilla and 1/4 cup of the melted butter. Pour the batter into prepared pan and bake for 35 to 40 minutes, or until toothpick inserted in center comes out clean. Let the cake cool in pan for 10 minutes before removing to wire rack to cool completely.