01 - Preheat oven to 350°F (175°C). Grease and line a 9x13-inch (23x33 cm) rectangular cake pan.
02 - In a bowl, whisk together flour, baking powder, and salt until evenly mixed.
03 - Using an electric mixer, beat butter and granulated sugar until light and fluffy, approximately 3 minutes.
04 - Add eggs one at a time, beating well after each addition. Stir in vanilla extract thoroughly.
05 - Add dry ingredients in three parts alternated with milk, beginning and ending with the dry mixture. Mix just until combined to avoid overmixing.
06 - Pour batter into the prepared pan and smooth the top. Bake for 30 to 35 minutes or until a toothpick inserted into the center comes out clean.
07 - Allow the cake to cool in the pan for 10 minutes before transferring it onto a wire rack to cool completely.
08 - Beat butter until creamy. Gradually add powdered sugar, beating until smooth. Incorporate vanilla extract and milk until the frosting is spreadable. Divide and tint with food coloring as desired.
09 - Once cool, cut and arrange cake pieces to form a house shape, using rectangles for the base and triangles for the roof.
10 - Frost the cake with colored buttercream to create walls, roof, and doors. Attach candies and wafer cookies for decorative accents. Optionally, add dyed shredded coconut as grass.
11 - Chill the assembled cake briefly to firm the decorations before serving.