Preheat the oven to 350°F. Next, beat the eggs with 1 cup of sugar until the mixture doubles in volume. In thirds, fold the flour into the egg mixture, being extra careful not to over mix the batter.
Spread the batter onto a baking sheet lined with parchment paper (10" X 15" is the perfect size). Bake for 12 minutes. Once to comes out of the oven, place a towel on top of the cake and roll it into a spiral. Set the cake aside to cool completely.
To make the frosting, use a stand mixer or hand mixer to beat the softened butter and half of the dulce de leche until smooth.
Next, add in the extra cold heavy whipping cream and whisk on high speed. Once it reaches stiff peaks, immediately stop whisking it.
Microwave the other half of the dulce de leche for about 30 seconds, or until it softens. Gently, unroll the cake and remove the parchment paper. Spread the dulce de leche onto the cake roll, followed by a layer of the dulce de leche frosting. Roll the cake back up and apply the remaining frosting to the outside of the cake.
Decorate the cake by sprinkling the top with crushed caramel candy or drizzling it with dulce de leche. Enjoy immediately or allow the cake to set in the refrigerator for an hour before serving!