I purchased this, elsewhere, for my son's birthday cake. I had planned on decorating each individual block the different colors of Lego blocks and then stacking them.
Silicone bake-ware is great. The problem with this mold(mould) lies in the "studs" (or the round part that sticks up). I followed the directions, I sprayed with baking spray and while all the rest of the cake came out, the studs didn't. They are so small that it was easier for the cake to come out and leave them behind.
I actually took my icing knife and scooped each one out and reattached them to the little squares, then iced.
What I ended up with were iced squares. The studs are so small that the icing, even minimal icing, covered them right up.
I finally just baked another cake, made cupcakes, put them on the sheet cake and iced the whole thing to make it look like one giant Lego block..at 1am.
Incidentally, I also learned that an entire bottle of red food coloring will not turn white icing red. It turns it pink. So buy the more expensive gel food coloring. I've been told it works better.