It is usually called a slap to a strong goal, either given or received. Hard fall, blow. Also a blow given with a cake. Daubed with a cake, usually at a celebration.
Hit given with a cake or cake. It actually extends to any punch, and this must come from the cake routines of clowns, who threw cakes (props, with soap scum cream) to their faces.
Smack: m. hit with a pie or omelette.