If using chocolate chips or something similar, instead of filling each cake you can gently stir them into the prepared batter and then fill the pans and bake. The yield will depend on the size of your mini bundt pan. I have the Nordicware Bundt Brownie Pan where there is an indent in top, but not a complete bundt hole like in the Nordicware Anniversary Bundtlette Pan or the Wilton Mini Fluted Pan. My pan makes 12 and the cakes are ⅓ cup, the other pans makes 6 and each is about one cup. With my pan this recipe makes 18, with the other it would be 12.