Add the flour, molasses, pumpkin pie spice, ginger, baking powder, and salt to the Basic Recipe dough. Divide in half and shape each piece into a disc. Wrap with plastic wrap and chill until firm, about 2 hours.
Preheat the oven to 350°F. Line 2 baking sheets with parchment paper.
Roll out a disc of chilled dough on a lightly floured surface to a scant 1/4-inch thickness. Use a 3- to 5-inch house shaped cookie cutter to cut out shapes, re-rolling scraps as needed. Use a sharp knife to cut out doors and windows, if desired. Transfer to the prepared baking sheets, about 2 inches apart. Bake until just golden around the edges, about 10 to 12 minutes. Transfer to a wire rack and cool completely.
Divide the Royal Icing into smaller bowls and tint as desired with food coloring. Place each color in a zip-top bag. Press out the excess air and seal the bags. Snip a very small corner from each bag, and pipe decorations on the cookies. Finish with candies as desired.
In a medium bowl combine the flour, baking soda, and salt.
In a separate large bowl beat the butter and sugars with an electric mixer until light and fluffy, about 2 minutes. Add the eggs, one at a time, beating well after each addition. Beat in the vanilla. Gradually add the flour mixture, beating until just combined.
Divide the dough in half, and proceed with a cookie recipe. (Each recipe uses half of the Basic Recipe.) To save the dough for later use, shape each half into a disc, wrap in plastic, and freeze for up to a month.