In a large mixing bowl, combine the flour, sugar, baking powder, salt and butter. You can use your electric mixer if you wish but mixing by hand works, too.
In a separate bowl, mix half and half and the egg; fold in the dry ingredients until just combined. Add the blueberries and stir well, using a large spoon or spatula.
Coat a loaf pan with vegetable oil spray and pour in the batter. Bake for 30 minutes until the top of cake is golden brown and a toothpick inserted into its center comes out clean.
Everyone loves a simple recipe for blueberry cake. You can whip up a loaf of this sweet bread in no time flat—it mixes up nicely by hand or with a mixer. I like to enjoy this cake when I work in my garden, serving up slabs of it in clean coffee filters; hence the name, “sleeve cake!”