Preheat the grill to 330°F, prepare for indirect cooking.
Spray two muffin tins with nonstick spray or line them with cupcake liners. If you wanted to you can just make a loaf or 4 mini-loaves out of this recipe too, but that defeats the grab’n’go purpose.
In a small bowl, mash the bananas and set them aside.
In a large bowl, cream the butter, yogurt, vanilla, brown sugar, and Splenda. Add the egg whites and the mashed banana to the yogurt mixture and beat on medium speed for 2 to 3 minutes.
Add the flour, salt, baking powder, and baking soda, gently mix them together until they’re blended, but do not overmix. Think of this like the brownie mixes, until combined, don’t beat.
Fill the muffin cups about ¾ of the way full. Grill bake for about 20 to 30 minutes, or until a toothpick comes out with a couple crumbs on them.
Remove the muffins from the grill and let them cool enough to touch. Then eat eat eat!