I made a Lego Birthday Cake Idea for my son's third birthday since he's always building “cakes” with his huge Mega Blocks. I looked at all the Lego cakes on your site to get ideas and then designed mine. I especially liked Lego cakes #16, 25 and 38 and followed #38 (thanks Lynn from CA!) the most.
I’m big into baking from scratch and using whole grains, so I made my own yellow cakes (baked four 9x13 cakes), let them cool, cut them into thirds and evened out the tops a little to make them flatter. I filled (raspberry, lemon, and plain buttercream frosting) and stacked them into six large blocks, crumb-coated them and froze them a week before the party. My son got the flu his b-day weekend, so we postponed the party a week and the cakes were fine in the freezer. I frosted and assembled them the night before the party. Used gel coloring for the frosting and would recommend less red than I used – it affected the flavor. And the colors got darker after the frosting set which made the blocks look better. Think I could’ve gotten away with less red and better flavor.
I used a basic buttercream frosting recipe for the taste so ended up with less perfect looking blocks, but found that after frosting each cake, if I wetted my frosting knife with warm water I could smooth each side and top of the block to be more uniformly smooth. Not perfect – but a definite improvement over my freehand skills. I followed Lynn’s suggestion of using tea light candle holders that I’d washed out to make the tops of the blocks. I only had aluminum ones, so I dishwashed them and filled them with frosting, then froze them. I used a butter knife and the warmth of my hand to get them out of the forms, then used warm water on the knife again to smooth them a little. Plastic would be easier! But it worked and they’re the perfect dimensions for this sized cake.
They were the kids’ favorite part of the cake. When my son first saw the cake from across the room on the morning of the party, he thought they were blocks. He figured it out fast and spent the rest of the morning trying to sneak frosting.