Heat oven to 180°C. Grease bottoms only of 2 (20cm) square pans with shortening or cooking spray.
Make cake batter as directed on box, adding almond essence with the water. Divide batter in half. Stir 2 drops blue food color into one half; stir 2 drops red food color into other half. Pour into pans. Bake as directed on box for 20cm pans. Cool 10 minutes. Run knife around sides of pans to loosen cakes; remove from pans to cooling rack. Cool completely, about 1 hour.
Place 1 cake layer on serving plate; spread with 110 grams white frosting. Top with second cake layer, bottom side down. Spread frosting evenly on side and top of cake. Decorate cake as desired to look like baby block, using decorating icing and decors. Store loosely covered at room temperature.