Created by Under15Cook on July 3, 2013
Step 1: Whisk together flour and baking powder in a small bowl.
Step 2: Beat together butter and sugar in a large bowl with an electric mixer at medium-high speed until pale and fluffy, about 3 minutes in a standing mixer or 6 with a handheld. Beat in egg and vanilla. Reduce speed to low, then add flour mixture and mix until just combined.
Step 3: Form dough into a 12-inch roll (2 inches in diameter) on a sheet of plastic wrap and roll up dough in plastic wrap. Chill dough 4 hours or until firm.
Step 4: Preheat oven to 375 degrees F.
Step 5: Cut roll into 1/4-inch-thick slices and place on large baking sheets about 1-inch apart.
Step 6: Bake for 10 to 12 minutes or until golden brown. Cool on sheets 3 minutes, then transfer to wire racks.