Lightly grease the baking dish and set aside.

Preheat the oven to 180C

Sieve the flour, bicarb, baking powder and salt three times to fully combine and set aside.

Put the eggs into a stand mixer bowl fitted with a whisk attachment and whisk on a high speed until fluffy.

Gradually add the sugars and whisk on high speed for about 5 minutes until creamy and volumized.

Whisk in the jam followed by the melted butter and vinegar.

Fold in the flour mixture alternately with the milk on a low speed. Finish folding in by hand to avoid overmixing.

Pour the mixture into the prepared baking dish and bake for approximately 35 minutes or until a skewer comes out clean.

Meanwhile make the sauce. Put all the ingredients into a small saucepan and gently heat, stirring frequently, until the sugar is dissolved. Turn up the heat and bring to a simmer for about 3 minutes.

Pour the source into two jugs, dividing it in half. Set aside.

Once the sponge is baked, remove from the oven and immediately pour over one half of the sauce.

Serve whilst still warm with cream, ice cream or crème anglaise, drizzled with some of the extra sauce.