Cake too dense/dry

[Odellae]

Heya!

I want to make a cake with the following ingredients:

170g oats
190g banana
115g whey protein powder
240g egg white, pasteurised

(extras used are baking powder, salt, liquid sweetener, vanilla extract, cooking spray)

I've made it twice now:
First time it went horribly wrong because the cake was so incredibly dry and dense.
Second time it went a lot better but still not /that/ great. I've already changed a lot of things in the process of making the cake:

Oats are turned into oat flower by using my food processor (can't get it fine enough to sift through a fine mesh strainer)
Banana is chopped until it's basically a paste
Dry and wet ingredients are first mixed seperately
Wet ingredients are mixed in a standmixer till soft peaks can be made
Wet and dry folded in together and then poured into a cake mold.
Baked at 180 degrees Celsius for about 20-25 mins (till fork came up clean after pricking in the middle)
Rested for about 30 minutes before slicing in

Are there any things I can add or change to make my cake more fluffy/moist?
Looking forward to seeing some of your replies!

 

[Mona]

To make your cake fluffier and moister, try adding 1/4 cup of unsweetened applesauce or Greek yogurt to your batter. Consider using 2 whole eggs instead of just egg whites to add moisture and fat. Make sure to add 1 teaspoon of baking powder if you haven’t already, and be careful not to overmix your batter. Also, double-check your oven temperature to ensure it’s accurate. These tweaks should help improve the texture of your cake!