In advance, make approximately 36 each of the following royal icing drop flowers: tip 224 in rose with tip 3 dot centers in white; tip 129 in violet with tip 3 dot centers in white. Make extras to allow for breakage and let dry.
In advance, cut steeple pattern from cookie dough and bake. Attach lollipop stick to back of cookie with royal icing; let set. Ice front of cookie smooth, add tip 4 bead border. Set aside.
Ice house front, back and sides smooth in buttercream on foil-covered board; ice roof using a spatula to create a shingle effect.
Trace door and window patterns with toothpick, with windows 1 in. from bottom of cake. Outline windows and door with tip 4. Pipe another tip 4 line next to outline. Pipe a third tip 4 line on top and between the first two. Overpipe the third line with a tip 2 line.
Edge windows and door with tip 3 dots. Pipe tip 4 center line on door and add tip 4 dot handles. Pipe tip 1D (smooth side up) band eaves on front of house. Pipe tip 16 zigzag garland on eaves.
Attach a drop flower at points of garlands; add tip 349 leaves. Pipe tip 4 outline doorstep.
Attach clusters of flowers around base of house. Insert steeple cookie on roof.
Using tinted piping gel in cut parchment triangles, pipe-in windows for stained-glass look.