In a medium-sized bowl, mash 1 large, ripe banana with a fork. Add 1 & 1/2 teaspoons fresh-squeezed lime (or lemon) juice and 1 teaspoon pure vanilla extract. Blend thoroughly and set aside.
In a chilled bowl, whip 2 chilled egg whites to a soft peak stage.
Gradually add 1 & 1/2 tablespoons confectioner’s sugar to soft peaked egg whites. Continue whipping egg whites on high speed until stiff peaks form.
Working in thirds, gradually (and gently) fold the stiffly beaten egg whites into the mashed banana until combined.
Spoon souffle mixture into 2 or 3 individual ramekins prepared with non-stick cooking spray; divide evenly.
Set filled ramekins on a cookie sheet (or jelly roll pan) and place in lower third of a preheated 450 degree F oven with upper rack removed.
Turn on the oven’s interior light and keep a close eye on your souffles. Resist the temptation to open the door during baking (to do so would risk the souffles falling prematurely). Bake for approximately 10-15 minutes.
When souffles are done, remove from oven and dust with confectioner’s sugar. Using a non-slip hot pad or thick, textured kitchen towel, remove ramekins to individual plates and serve immediately.