Line a standard 12-cup muffin tin with muffin liners or generously grease.
In a medium bowl whisk together flour, baking powder, baking soda, cinnamon and salt. Stir in oats.
In the bowl of a stand mixer, fitted with the paddle attachment, beat honey and butter on medium-high speed until fluffy, about 2 minutes. Add eggs and vanilla; mix just until combined. Add mashed bananas and milk; mix just until combined.
Mixing on low speed, add oat mixture to wet ingredients, scraping down sides with a spatula as needed.
Spoon batter into prepared muffin tins, filling muffin cups about 3/4 full. Bake 30 minutes, or until a knife inserted in the center comes out clean.
Cool muffins in tin on wire rack for 15 minutes. Remove individual muffins from pan and place back on rack to cool completely.