Banana Guglehupf is one of the newer additions to the Austro-Hungarian pastry roster. I've made countless American-style banana breads before, but this is a very special recipe, creating a beautiful fluted loaf filled with moist, banana flavor. Use fully ripened bananas freckled with brown spots with an intensely sweet aroma, and not ones that are overly ripe and blackened and smell of alcohol.
2. Beat the butter in a medium bowl with a hand-held electric mixer on high speed until smooth, about 1 minute. Reduce the speed to low and gradually add the confectioner's sugar. Return the speed to high and beat until very light in color and texture, about 2 minutes. One at a time, beat in the eggs, beating well after each addition.
3. Sift the flour, baking powder, and salt together and set aside. In another medium bowl, whisk the bananas, brown sugar, cream, and lemon zest until the sugar is dissolved. With the mixer on low speed, one third at a time, alternately beat in the flour and banana mixtures, scraping down the sides of the bowl often, until the batter is smooth. Pour into the pan and smooth the top.
4. Bake until the top is golden brown and a toothpick inserted in the center of the cake comes out clean, 50 to 60 minutes. Cool in the pan on a wire cake rack for 10 minutes. Invert onto the rack and cool completely.
Make-Ahead The cake can be made up to 1 day ahead, covered with plastic wrap and stored at room temperature.