Preheat oven to 350 degrees F (175 degrees C). Line a muffin tin with with paper liners.
Beat sugar and shortening together in a large bowl with an electric mixer until light and fluffy. Beat in eggs one at a time.
Sift flour into the shortening mixture. Add bananas, buttermilk, salt, baking soda, and baking powder; mix until well combined. Spoon batter into the prepared muffin tin, filling each 2/3 full.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 20 to 22 minutes.