Building upon the leavening agents suggestion, maybe she could also incorporate whipped egg whites to lighten a cake (no chemical reaction) and compare which has the lightest texture or crumb.
It's what I use for Red Velvet instead of cream cheese frosting. Not sure if you've made this before.. If not, the sugar is granulated not powdered and it has to be whipped for a long time to lose the grittiness. So worth it. Good luck!...
My favorite is Hummingbird Cake. It is a banana and pineapple spice cake (can add carrots or coconut too) with cream cheese frosting and OMG GOOD made with vanilla bean paste.
Brownie pops (like cake balls but brownie inside)Southern PralinesLemon barsmini pecan piesCan you tell I'm a southern girl? My favorite warm weather cake ball flavor is Key Lime with graham crumbs decorating the top