I played around with the wasc recipe and made a strawberry version that has great taste. I pureed frozen (unsweetened) strawberries and added 1 cup of that as part of my liquid. I baked them off as cupcakes and the flavor was wonderful and the texture was moist and light but they barely rose at all - didn't even make it to the top of the paper and the center sank just a bit. The regular wasc recipe I use calls for 1/4 tsp. baking powder. Would substituting baking soda instead of the baking powder help the leavening due to the increased acid content of the strawberry puree? If I should swap, how much soda would I use? Or should I keep the baking powder and add a bit of baking soda too? Again, how much? Or am I completely off base and I need to do something else entirely? TIA

You have a lot of extra liquid and sugar from the strawberries in there. The WASC I use sometimes doesn't call for extra leavening. If I were to add strawberries I would definitely cut the sugar back at least 1/2 cup. Even though the fruit doesn't have any extra sugar it still has natural sugar and acids which affect the pH of the batter.

Do you have the Cake Mix Doctor book? She has a strawberry one in there that calls for real fruit but I don't have it here right now to give you the recipe. There are at least two or three strawberry cake mix recipes in her book. Good luck!