Mash the 2 bananas and 1/4 cup peanut butter in a medium bowl with a potato masher until well combined.
Add the 2 tablespoons sugar, 2 teaspoons baking powder, 1 teaspoon cinnamon, and 1/2 teaspoon kosher salt. Stir with a silicone spatula until evenly mixed.
Sprinkle the flour over the top and gently mix in with the spatula. Batter will be thick.
Pour about 2 inches of oil into a deep pot and heat over medium heat until it reaches between 340°F-350°F on a candy/deep fry thermometer, or until a piece of bread dropped in the oil browns in 30 seconds.
Using a cookie scoop, if you have one, scoop the batter and carefully drop 4-5 fritters at a time into the hot oil. Fry for 3-4 minutes, turning halfway through.
Remove fritters to a paper towel-lined tray and repeat with the remaining batter.
Serve fritters warm, dusted with powdered sugar and drizzled with coffee sauce. They are best enjoyed right away.