In a mixing bowl, beat the egg yolks until creamy.

Add the heavy cream and sugar, and mix well.

In another clean bowl, beat the egg whites until stiff peaks form.

Gently fold half of the beaten egg whites into the yolk mixture until combined.

Heat a frying pan over medium heat and melt the butter in it, being careful not to brown.

Pour the egg mixture into the pan and cook carefully, lifting the pan from the heat occasionally to prevent scorching on the bottom.

When the omelette is nearly set, pour the remaining egg whites over the top and sprinkle with powdered sugar.

Transfer the pan to a preheated oven and cook until the egg whites are set.

Meanwhile, heat the fruit preserves or jelly in a small saucepan until warmed.

Once the omelette is cooked, carefully transfer it onto a hot serving platter.

Spoon the warmed fruit preserves or jelly over the omelette.

Fold the omelette in half quickly and serve immediately.