Preheat the oven to 450 degrees F (230 degrees C). Grease an 8-inch baking pan.

Sift flour, sugar, baking powder, salt, and nutmeg together in a large bowl. Cut in butter with 2 knives or a pastry blender until mixture resembles coarse crumbs. Beat together milk and egg in a small bowl; stir into flour mixture until batter is just blended. Spread batter in the prepared baking pan.

Bake in the preheated oven until golden, about 15 minutes. Cool in the pan for 10 minutes before removing to cool completely on a wire rack.