My kids love helping with these — tossing handfuls of spinach in the blender, scooping out the avocado and, of course, adding the chocolate chips (which always need a taste test!). And although the spinach and avocado aren't front and center taste-wise, the kids understand that these healthy foods are key ingredients in their favorite muffins — and are a little more willing to give them a shot when they see them on their dinner plates.
Technique tip: A cookie scoop makes quick work of filling the muffin tins. And don't be alarmed if your batter has a green ting to it; the muffins will darken as they cook and turn a rich brown.
Swap option: For added fiber, replace 2/3 cup of the all-purpose flour with whole wheat flour (for a total of 1 cup all-purpose flour plus 2/3 cup whole wheat flour). Avocado not ripe? Skip it and add more oil instead, 1/3 cup total canola or avocado oil. If the batter is on the extra thick side for this non-avocado version, add a splash more milk.
Preheat the oven to 350 F. Spray a 12-cup standard muffin tin (or two mini muffin tins) generously with cooking oil spray, or line with paper liners sprayed with cooking oil spray.2.
Blend the spinach, milk, avocado, oil, egg and vanilla in a blender until the mixture is very smooth and you don't see pieces of spinach, just green milk. If you are having trouble blending because the mixture is too thick, add a splash more milk.3.
In a large bowl, whisk the flour, cocoa powder, brown sugar, baking powder, baking soda and salt until they are combined, then stir in the spinach mixture. It's fine for the batter to be thick, but if it's so thick you are having trouble combining, add a splash more milk. Fold in 1 cup of the chocolate chips until they are just incorporated.4.
Pour the batter into the prepared muffin cups, filling them almost to the top. Sprinkle the muffins with the remaining 1/4 cup chocolate chips. Bake the muffins, rotating the muffin tin(s) once halfway through the baking time, until they puff up and a toothpick inserted into the center of a muffin comes out clean — for regular-sized muffins, about 20 minutes, and for mini muffins, 10 to 13 minutes.5.
Allow the muffins to cool for 5 minutes before removing them from the tin, then transfer the muffins to a cooling rack. Once cool enough to eat, devour!