General Recipe Trouble Shooting

I bake all of my muffins in oversized muffin tins that are not "Texas sized," but just a taller version of the regular size. With just a few adjustments to baking time, all of my muffins turn out beautifully - except one. One recipe for banana muffins always winds up with a wet spot in the middle even though the "toothpick test" right into the very area seems to be okay.