Double-Chocolate Muffins

Preheat oven to 350°F and line 10 muffin cups with paper liners. In a large bowl, whisk together avocado, oil, maple syrup, and brown sugar. Whisk in egg, vanilla, baking powder, baking soda, salt, and milk.

Whisk in cocoa powder, then stir in flour until combined. Fold in chocolate chips. Divide among cups and bake 10 minutes. Sprinkle with a few more chocolate chips and sanding sugar; return to oven and bake until a tester inserted in centers comes out clean, 8 to 10 minutes more. Let cool and serve, or store, covered, at room temperature up to 3 days.