In the book, Rosenberg writes that the cake is really "a blueberry muffin masquerading as a cake." After I made it, the cinnamon streusel-topped cake tasted more like a really sweet coffee cake than a blueberry muffin. With all that sweetness, the flavors of the blueberries sort of disappeared. I wondered if I could steer the recipe in a less sweet, more muffin-like direction.
The first thing I did was reduce the granulated sugar in the batter by a quarter of a cup. Not a huge reduction, but one I felt confident wouldn't affect the cake adversely. Sometimes when you remove too much sugar from a cake recipe, the cake flops. I also got rid of the brown sugar streusel topping, which contained a full cup of sugar. Between reducing the amount of sugar in the batter and getting rid of the streusel topping completely, I hoped the flavors of the flours and blueberries would come through. The first attempt at the recipe made a cake that simply tasted sweet.
I also changed the method. The original recipe called for creaming the butter and sugar together. I wanted to see if cutting the fat into the flour, as you do for biscuits, would lighten the texture of the cake.
The resulting cake baked up wonderfully high. In fact, the texture of the cake reminded me slightly of the bisquick-based muffins my mom baked during my childhood. Reducing the amount of sugar and omitting the streusel had just the effect I wanted. The cake tasted like blueberries and wasn't too sweet. As for those blueberries, they tend to sink to the bottom of the cake, even after they've been tossed in gluten-free flour. I don't find this bothersome. In fact, I'm delighted when my fork hits the the layer of blueberries on the bottom of the cake.
Since this recipe makes such a tasty muffin-like cake, I decided to go ahead and bake a batch of muffins with it. The recipe performed perfectly. And since we're headed into fall and fresh blueberries will all too quickly disappear from the market, I made that batch with frozen blueberries. That worked too! So whether you make this recipe as a cake or muffins, with fresh blueberries or frozen, you'll be treated to a light, flavorful breakfast treat that isn't too sweet.