<<Disclaimer: Verify this information before applying it to your situation.>>

Several have asked me what cake recipes do I use with the crumb
toppings.  The answer is any and all.  I use any cake recipe that calls
for cake flour.  Then I use corn starch as a substitute.  I even use
cornbread [with added sweetener] when I want it to travel well.

One thing I do, tho, is to add additional spices to the cake batter
itself.  for example, if the topping has cinnamon and nutmeg in in, I
add about 1/2 teas cinnamon and a pinch of nutmeg to the batter.  It
echos the flavor nicelly.

Ann