I wasnt sure if this is more a "disaster" or a how to but Id like help if anyone can advise which is why I put the topic here.

I made almond (with a full cherry in the middle of half of them) cupcakes for a friends birthday a few months ago, they rose beautifully but even before I opened the oven to check if they were done they sank in, really really badly! They tasted really nice but clearly couldnt be presented in any sort of formal setting (and my friends wife is lactose intollerent and cant have much saturated fat so disguising with a large buttercream swirl wasnt an option!) This is the recipe I used:
4 eggs (separated with the whites whisked separately)
175g/ 3/4 cup caster sugar
225g/2 ¼ cup ground almonds
½ tsp baking/bicarb soda and 1tsp cream of tartar
Candied/glace cherries (1 per cupcake)

Im guessing its the amount of raising agent that is the problem but I dont know enough about the science to know exactly what and how to correct it. Would anyone be kind enough to help please?
The reason I particularly want to know now is that two of my cousins were diagnosed with wheat intolerances last week so if I could get this recipe sorted Id be able to make it for them.

Thank you for any suggestions or assistance!

I have baked many spongecakes with all nuts but never any leavening. Try this recipe without the soda or cream of tartar. Whisk the yolks and half sugar until fluffy, whisk the whites and rest of sugar to firm peaks. Add nut flour and then yolks on top of meringue and fold together gently. You can also use ground hazelnuts or walnuts. For chocolate, add a few tablespoons baking cocoa.

Thanks, I'll try just leaving out the leavening.
The chocolate hazelnut sounds wonderful too so I'll have to try that too!

How about trying baking powder instead of baking soda/tartar maybe just 1/2 tspn.