In a food processor pulse vanilla wafers until reduced to crumbs. Continuing to pulse, add 1 teaspoon of the sugar and salt, then slowly drizzle in butter until completely combined. Divide mixture in half and pour into ramekins. Using the bottom of a small glass, press the crumbs into the ramekins to make a crust on the bottom. The crust should be about 1/4-inch thick.
In a medium bowl combine banana, brown sugar, peanuts and chocolate chips. Divide this mixture in half and place in the bottom of each ramekin. In the same bowl, whisk together yolks, heavy cream, vanilla, zest and remaining 1 teaspoon of sugar until sugar is dissolved. Pour evenly into both ramekins and bake for 30 to 35 minutes or until a knife inserted in the center comes out clean.