In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Add sugar; beat until combined, scraping sides of bowl occasionally. Beat in 1 tablespoon milk and 1 teaspoon vanilla. Beat in as much of the flour as you can with the mixer. With a wooden spoon, stir in spirnkles and any remaining flour.
Divide dough in half. Cover and chill about 1 hour or until dough is easy to handle. On a large sheets of parchment paper roll out dough portions to 1/8- to 1/4-inch thick. Lightly flour top of the dough as necessary to keep it from sticking to the rolling pin.
Using a gingerbread house template, set pattern pieces on the dough; use a sharp knife to cut around each pattern piece. Remove excess dough. Remove pattern pieces; set aside.
Transfer dough cutouts on parchment paper to a large cookie sheet. Bake in the preheated oven for 12 to 15 minutes or until edges are lightly browned. Cool 2 minutes on pan. Remove to wire racks and cool completely. Use a knife to cut edges evenly, if necessary.
Assemble cookie house, using royal icing as glue. Let stand until firm. Decorate as desired with royal icing, candies, and decorative sprinkles.