When making our mallet rather then constructing it out of a solid piece of wood we laminate the head around a solid core. This prevents the head from splitting out when hit repeatedly. The component of the lamination that actualy makes it stronger is the fact that we make quarter sawn wood essentially. We start with a solid piece of 5/4 hard Mape around 2 inches long. We mill it flat to maximum thickness and then cut it into 3rds. We then stack those thirds and laminate them all together. That sandwhich is then cut into thirds with the direction of the grain. When those pieces are flipped and applied around the hand the grain is perfectly quartered. Although this is a very brief break down of the process as always if anyone has questions please ask. I will answer as quickly as I can.
This process is also the same process that would be used to make solid cores for veneered tops and panels. The advantage of this is that quarter sawn material expands and contracts in its thickness and not in its width helping the veneering from splitting or fracturing.