Mix flour, sugar and baking powder in bowl. Add milk, beer and egg and stir until smooth.
Heat oil in deep fryer or heavy deep skillet to 375F. Working in batches, dip bananas into batter and then carefully add to oil. Cook until golden brown, about 3 minutes. Drain on paper towels. Pour caramel sauce onto plates. Set bananas atop sauce. Sprinkle with powdered sugar. Garnish plates with mint leaves and serve.
Bring cream to boil in heavy medium saucepan over high heat. Cook sugar in heavy small saucepan over low heat, swirling pan occasionally, until brown. Gradually stir hot cream into caramel (mixture will bubble vigorously). Boil until thickened to sauce consistency, 3 to 5 minutes. Add bourbon. Serve hot. (Sauce can be prepared 1 day ahead. Cover and refrigerate. Rewarm over low heat.)
Makes about 1-1/3 cups.
Recipe from Brennan's of Houston, Courtesy of Bon Appetit, October, 1987