Steps
1. In a bowl, whisk together the banana puree, milk, egg, sugar, and vanilla extract until smooth.
2. In another bowl, sift together flour, baking powder, baking soda, salt, and cinnamon.
3. Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Do not overmix.
4. Heat oil in a deep pan to 350°F (175°C).
5. Using a spoon or piping bag, drop donut batter into the hot oil, forming small rounds.
6. Fry each side for about 2-3 minutes or until golden brown and puffed.
7. Remove donuts and place on paper towels to drain excess oil.
8. Dust with powdered sugar while still warm.
9. Serve immediately and enjoy the fluffy banana milkshake flavor in every bite.