Preheat the oven to 350°F (175°C).
Prepare the cake batter by whisking together the cake flour, salt, and half of the granulated sugar.
In a separate bowl, whip the egg whites until foamy. Gradually add the remaining sugar and whip until stiff peaks form.
Gently fold the flour mixture into the whipped egg whites, being careful not to deflate the mixture.
Pour the batter into a 9-inch angel food cake pan and bake for 35-40 minutes.
Remove from the oven and let the cake cool upside down in the pan. Once cooled, remove from the pan.
Cut the cake into bite-sized pieces and dip in melted butter, then coat in a mixture of cinnamon and powdered sugar.
Heat oil in a deep skillet or fryer and fry the coated pieces until golden brown, about 2-3 minutes per side.
Drain on paper towels and serve warm for the best texture and flavor.