From Chef Oonagh Williams of Royal Temptations Catering
This is based on a wheat-flour recipe from a local farm stand in New Hampshire. It’s one of those recipes that requires only ingredients you probably already have and plenty of fresh fruit. I made it with a mix of fresh strawberries, peaches and blueberries, then I made a version with just blueberries. In New Hampshire, we can get tiny Maine wild blueberries, but regular blueberries are fine. If you use frozen berries, the cooking time will be significantly longer and the cake far moister. Note that if you use a strong gluten-free flour with lots of brown rice or bean flour, it will be dryer and you will need to add 1-2 Tbsp. more buttermilk. I put this quantity in 1 x 9” cake pan and next time divided it between the 2×8” shallow holes of a Wilton Giant whoopie pie pan. In New Hamshire, we can easily buy fresh buttermilk, not processed.
For an egg-free version, I have used a substitute of 1+1/2 Tbsp. water, 1+1/2 Tbsp. oil, and 1+1/2 tsp. baking powder as a 1 egg substitution in addition to ingredients below. I find it’s more of a shortbread style finish not a cake. This recipe can be easily made dairy-free as well.