Spray a 13-by-18-inch rimmed baking sheet with cooking spray. Whisk together the flour and baking powder in a medium bowl.

to cream butter with both types of sugar and orange zest until creamy, but not too white and fluffy. Add egg and beat until fully combined, then add flour mixture, followed by currants and chopped ...

Remove ½ cup of the glaze to a medium bowl. Stir in the food coloring to make a deep orange color. Pour the white glaze over the cake, spreading with an offset spatula to cover. Drizzle the ...