Combine 1/2 teaspoon of the sugar with the cinnamon. Place the fruit in a small bowl and add the cinnamon-sugar. Toss to combine.
Heat the 3 tablespoons of butter in a small saute pan over medium heat. Add the fruit and saute for about 5 minutes or until the fruit begins to caramelize. Remove from the heat and set aside.
Preheat the oven to 375 degrees F.
Using an electric mixer, beat the egg whites until stiff peaks form. Using an electric mixer, beat the egg yolks with the remaining sugar until very light and fluffy. Fold in the vanilla and lemon zest. When well blended, fold in the beaten egg whites.
Pour the melted butter into a 7-inch, ovenproof omelette pan over medium heat. Place the fruit (if sliced, fan it out) into the pan and pour in the batter to cover the fruit. Cook for 1 1/2 minutes. Place in the preheated oven and bake for about 10 minutes or until the omelette is puffed and golden.
Remove from the oven and carefully invert onto a serving plate. Dust with confectioners' sugar and serve. NOTE: If desired, you can garnish the plate with fresh fruit and mint.