Preheat oven to 375°F. Place cupcake wrappers in a muffin tin; set aside.
Mash bananas and add to a large mixing bowl. Stir in honey, vanilla, yogurt, and egg.
Heat coconut oil just until melted and carefully add to the mixture (if too cold it will harden, if too hot it will begin cooking the egg). Stir until well blended.
Add in cocoa powder, flour, salt, and baking soda. Mix just until fully incorporated; avoid over-mixing.
Fold chocolate chips and walnuts into the batter, then scoop evenly into the prepared cups.
Bake for 15-17 minutes. Serve warm.