Preheat the oven to 350°F. Line 18 muffin cups with paper liners.
In a medium bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon.
In a large bowl, whisk together the melted butter, granulated sugar, and brown sugar until smooth. Whisk in the eggs one at a time, then stir in the vanilla.
Mix in the mashed bananas and sour cream until well combined.
Add the dry ingredients and gently fold just until combined. Do not overmix.
Fold in the mini chocolate chips.
Divide the batter evenly among the muffin cups, filling each about ¾ full.
Bake for 18–22 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs attached.
Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.
Whisk together the powdered sugar, milk, corn syrup, vanilla, and salt until smooth. If the glaze is too thick, add a little more milk. If it’s too thin, whisk in a little more powdered sugar.
Spoon or dip the tops of the cooled muffins into the glaze.
Let the glaze sit for 2 to 3 minutes, until it begins to lose its shine but is still tacky. Gently press one baked and cooled Pillsbury™ Minions Shape™ Sugar Cookie onto the center of each muffin.
Let the muffins sit at room temperature for 30–60 minutes, or until the glaze is completely firm before serving or packaging.