01 -
Preheat oven to 350°F and prepare two standard 12-cup muffin pans with nonstick spray or paper liners.
02 -
In a large mixing bowl, whisk together butter pecan cake mix, all-purpose flour, and baking powder until thoroughly blended.
03 -
Add mashed bananas, eggs, and 1 cup of chopped walnuts to the dry ingredients. Stir by hand just until all components are evenly combined, avoiding over-mixing.
04 -
Divide the batter evenly among muffin cups, filling each approximately two-thirds full.
05 -
Sprinkle the remaining 1/2 cup of chopped walnuts evenly over the surface of each muffin.
06 -
Bake in the center of the oven for 17 to 20 minutes, or until muffin tops are golden and a toothpick inserted into the center emerges clean.
07 -
Let muffins rest in the pan for 5 minutes before transferring to a wire rack to cool completely or serve them warm.