Heat oven to 350°F. Grease and flour 9 x 5 x 3-inch loaf pan and 13 x 9 x 2-inch baking pan. Line bottom of larger pan with waxed paper.
Mix flour, soda, ginger, cinnamon, nutmeg, cloves, salt.
Beat butter and sugar in bowl until fluffy, 3 minutes. Add eggs and rind; beat to combine. Stir molasses and water in measuring cup. On low speed, beat flour mixture alternately in thirds with molasses into butter mixture, beginning and ending with flour mixture. Scrape batter into 9 x 5 x 3-inch loaf pan.
Bake in 350°F oven until pick inserted in center comes out clean, 1 hour. Cool in pan on rack 10 minutes. Remove from pan; cool on rack.
Make second batch of cake batter. Scrape into 13 x 9 x 2-inch baking pan. Bake in 350°F oven for 45 minutes. Cool as above, removing waxed paper.
Bring milk and flour to boiling in small saucepan over medium heat, stirring constantly, until thick, 12 to 15 minutes. Place waxed paper on top. Cool to room temperature.
Beat butter and sugar in bowl until very fluffy, 3 minutes. Add vanilla and cooled flour mixture; beat until frosting is very fluffy, about 10 minutes. Remove 3/4 cup frosting to small bowl; tint green.
Trim crown off loaf pan cake so top is level. Make 2 lengthwise cuts from center of cake to both long bottom edges to create large triangle roof. Save remaining pieces for attic window and for snacking.
Cut 13 x 9-inch cake lengthwise into thirds to make three 9 x 3-1/2-inch pieces. Spread scant 1/3 cup frosting on all 3 pieces. Stack on top of each other. Place triangular roof on top. Cut attic window from reserved cake trimmings. Affix to roof, securing with picks. Frost roof and sides of house. Decorate roof with cereal for shingles. Use chocolate candy bar for windows; fruit leather for door. Decorate house with candies. Pipe green frosting for evergreen boughs.