Goomba38 wrote:

Have you tried to bake the cake portion partially, then add the topping
midway and then finish the baking?

Wouldn't that make the half-risen-but-not-yet-firmed portion totally
deflate? Guess you could distribute the topping to hide that, but the
density would change a bit through the cake.

To the OP - any reason you want *that* particular recipe? Should be
dozens of crumb cake recipes out there... Why not try a new one?

-j.