In a small bowl, stir together 6 tablespoons warm water and yeast. Let stand until foamy, 5 to 10 minutes.
In the bowl of a stand mixer fitted with the paddle attachment, stir together flour, granulated sugar, salt, cinnamon, and baking soda. Add yeast mixture, buttermilk, egg, butter, and rum extract, and beat at low speed just until a dough forms. Switch to the dough hook attachment, and beat at low speed until dough is smooth and elastic, about 5 minutes. (Dough should stick to bottom of bowl but not sides.)
Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover with plastic wrap, and let rise in a warm, draft-free place (75°) until doubled in size, 45 minutes to 1 hour.
In a large Dutch oven, pour oil to a depth of 3 inches, and heat over medium heat until a deep-fry thermometer registers 350°.
On a lightly floured surface, roll dough to ¼-inch thickness. Using a sharp knife, cut dough into 2-inch squares. (Do not reroll.)
Fry dough in batches until golden brown, 2 to 3 minutes per side. Let drain on paper towels. Dust confectioners’ sugar onto beignets. Serve warm with Bananas Foster Sauce.
Bananas Foster Sauce
In a large skillet, melt butter over medium heat. Add brown sugar and cinnamon, stirring until sugar dissolves. Remove from heat; slowly stir in rum. Return to heat; cook until mixture is slightly thickened, 2 to 3 minutes. Add banana slices, and cook for 1 minute. Use immediately.
Recipe by Louisiana Cookin' at https://louisianacookin.com/bananas-foster-beignets/