Preheat oven to 350°F. In a medium bowl, add flour, baking powder and salt. Using a whisk, stir to combine and get the lumps out. Set aside.
In a large bowl, add butter and beat with an electric mixer on medium for 1-minute. Turn to low and gradually add sugar. Turn to medium and beat 3-minutes. Add the egg and vanilla and beat another minute. With the mixer on low, gradually add the flour mixture.
Blend until the dough begins to pull away from the sides of the bowl. Place dough on a large piece of parchment paper. Use your hands to knead the dough for a few minutes. Divide the dough into two sections and wrap with parchment paper. Let chill in the refrigerator for about 30-minutes.
To roll dough, place another piece of parchment paper on top of dough and roll with a rolling pin until the dough is between ⅛" and ¼" thick. Cut into 3" hearts and remove the excess dough. Place hearts on an Hestan OvenBond Quarter Sheet Pan. Bake for 10-13 minutes or until slightly golden brown around the edges. Let them cool and decorate with royal icing.
