I used this recipe that I found online:
100g oat flour (used bob's red mill)
60g protein powder (used syntha 6)
15g dark cocoa powder
1/4 cup sweetener (I used truvia)
1/2 tsp baking soda
1/4 tsp salt
30g chocolate chips
1/4 cup unsweetened almond milk
1 whole egg (53g)
2 egg whites (60g)
2 ounces greek yogurt
Bake @ 350 for 25 mins
Mine came out really dry. When I press down on the cake it makes a gross spongy sound.
What can I add to make the cake more moist (without butter/oil)?
You could brush it with a flavored or plain simple syrup
Oooops, just noticed you didn't use sugar in your recipe, cant think of a substitute
AI have no idea about the science behind cake recipes but maybe try adding simple syrup before filling and stacking the cakes. It's just a mixture of equal part sugar and water heated on the stove until the sugar is dissolved, and brush on the cake once it's cooled.