In a large bowl, combine flour, ginger, cinnamon, nutmeg, baking powder and salt.
In a separate large bowl, beat butter with an electric mixer until creamy. Gradually add sugar and beat until light and fluffy. Add flour mixture, a little at a time, and beat until mixture forms a stiff yet pliable dough. Turn out onto a floured work surface and knead into a ball. Wrap in plastic and refrigerate until completely chilled, at least 2 hours.
Preheat oven to 400°F and line 2 large baking sheets with parchment. Roll out dough to 1/4-inch thickness. Cut out cookies with a 2-inch heart-shaped cookie cutter. Place cookies about 1 inch apart on baking sheets. Bake until cookies are firm in center, about 10 minutes. Let cool on wire racks. Repeat with remaining dough.