Preheat the oven to 325°F, and grease a 7” x 11” baking dish.
Crush the vanilla wafers in a large sealable plastic bag or a food processor. Mix the melted coconut oil with the cookie crumbs until a kind of dough forms, and press the mixture into the bottom of the baking dish.
Next make the cheesecake filling in a large bowl. Combine the cream cheese, sugar, and bananas. Use a mixer on medium speed to beat them together. The mixture should be smooth except for small clumps of banana. Mix in the yogurt and vanilla extract, and then one at a time, beat the eggs into the cheesecake batter.
Pour the Greek yogurt cheesecake filling into the baking dish, and spread evenly over the wafer crust. Bake on the center rack for a half hour, until the center is mostly set.
The cheesecake must set completely before cutting it into bars. Let cool on the counter for at least 45 minutes, and then set in the fridge for three hours.
Slice into 15 bars, and (finally) sink your teeth in. Cover any leftovers, and keep in the fridge.