I used unsalted butter, 1 tsp salt, frozen blueberries, and two peaches; also added 1 tsp vanilla, 1/2 c ground flaxseeds, and 2 tsp cinnamon to the batter, and omitted the topping. They ended up baking for 30 minutes - still batter-y at 20, and at 25. Tasty tasty though, and kid-approved! Next time I'll use a cup of whole wheat flour in place of the all-purpose.