Aquafaba stands in for eggs in these vegan banana muffins, and they still rise high with a tender, bakery-style crumb. Spotty bananas, coconut sugar and a cinnamon streusel top make them feel like dessert you can eat at breakfast.
Heat the oven to 425 °F with a rack in the middle. Grease the bottoms and sides of a standard 12-cup muffin tin, or use a silicone muffin pan.
Stir the lemon juice into the oat milk and set aside for 7 minutes.
Shake the can of chickpeas to distribute the starches, then measure the aquafaba into a blender. Blend on medium speed until uniformly foamy, about 1 minute. Add the oat milk mixture, vanilla, bananas, coconut sugar and coconut oil and blend on medium until no banana lumps remain.
Mix the flour, walnuts, salt, baking soda and cinnamon in a large bowl. Pour the wet ingredients over the dry and stir gently until just combined; a few streaks of flour are fine. Divide the batter among the muffin cups, filling them to the top.
Make the streusel: In a small bowl, mix the flour, coconut sugar, cinnamon, salt and maple syrup until well combined. Crumble it evenly over the muffins with your fingertips, covering the batter completely.
Bake for 5 minutes, until the muffins have risen. Without opening the oven door, reduce the heat to 350 °F and bake until a toothpick comes out clean or with a few crumbs, about 17 minutes more (22 minutes in a silicone pan). Let cool for 20 minutes before serving.
Notes
Ripeness Tip: Use spotty, overripe bananas for the most sweetness and moisture. Frozen ones work too; see how to freeze bananas, then thaw and include any liquid.
Aquafaba Tip: Use the liquid from a can of unsalted chickpeas so the muffins don't taste salty.
Nut-Free: Leave out the walnuts, or use chopped dark chocolate. Pecans also work if nuts aren't a concern.
Storing: Keep cooled muffins in an airtight container at room temperature for up to 2 days, or freeze them for up to 3 months.