Slice the bananas. Melt the butter in a small skillet over medium heat. Once melted, add the sliced banana and brown sugar. Cook the banana in the butter and brown sugar until the slices turn golden brown and slightly sticky. Remove the skillet from the heat.

Spread the peanut butter over half of the quesadilla. Scoop the caramelized banana slices onto the peanut butter. Sprinkle a dash of cinnamon on top. Fold the empty half of the tortilla over the filled side.

Place the quesadilla in a clean dry skillet and cook over medium heat until golden brown and crispy on both sides. Slice the quesadilla into triangles using a large knife or pizza cutter, then serve.