If you're like me and never actually have buttermilk on hand when you need it, you can make up a quick substitute by measuring out 3/4 tsp of white vinegar into a liquid measuring cup and then filling up to the 1/4 c mark with whole milk. Let it sit on the counter for a few minutes and it should start to thicken up a bit like buttermilk.
Source: Adapted slightly from Just a Taste Yield: 2 dozen standard sized muffins
2 cups of flour (all-purpose)
3/4 cup of granulated white sugar
1/2 tsp of salt
3/4 tsp of baking soda
3 very ripe bananas (the riper the better!)
6 Tbsp of butter (melted and cooled)
1-1/2 tsp of vanilla extract
1/4 cup of buttermilk (or buttermilk substitute)
2 medium zucchinis
In a medium sized bowl, whisk together flour, sugar, salt, and baking soda.
In a separate large bowl, mash bananas, then add eggs, butter, vanilla, and buttermilk. Mix well. Slowly add dry ingredients to the wet ingredients and stir until just incorporated.
Grate your zucchini and squeeze out the excess liquid before adding to the batter. Gently fold the zucchini into the batter.
Scoop the batter into standard sized muffin tins and bake at 350 ℉ for 16-18 minutes, or until a toothpick inserted in the center comes out clean. Cool on a wire rack and enjoy!