Preheat your oven to 375°F.

In a large mixing bowl, combine the flour, brown sugar, baking powder, salt, and chilled butter. You can use an electric mixer or simply mix by hand until the texture is uniform.

In a separate smaller bowl, whisk together the half and half and the egg.

Gently fold the wet ingredients into the dry mixture until just combined.

Add the blueberries and stir well using a large spoon or spatula, being careful not to overmix.

Coat a standard loaf pan with vegetable oil spray and pour in the batter.

Bake for 30 minutes, or until the top of the cake is golden brown and a toothpick inserted into the center comes out clean.