Place all the ingredients for the lemon syrup into a saucepan and bring to a boil. Turn down the heat and allow to simmer until the mixture has reached a light syrup consistency. Remove from heat and allow to cool.

To make the sponge, preheat your oven to 160°C/ 140°C fan/Gas mark 3.

Grease and line a Le Creuset Heart-Shaped Springform Tin with baking paper. Using an electric mixer with a paddle attachment, cream the butter, sugar, and lemon zest until fluffy and pale in colour. Add the eggs one at a time, mixing well in between each addition.

Sift together the flour and baking powder. Add the dry ingredients and milk to the creamed butter and sugar. Mix until just combined.

Bake for 80 minutes or until a skewer comes out clean. Remove from the oven and place on a Le Creuset cooling rack. Using a skewer, prick the cake and pour the syrup over. Allow the cake to cool for 20 minutes, then remove it from the tin. Allow the syrup-soaked cake to cool completely.

To make the lemon buttercream, place a small casserole on the stove and fill 1/3 of the way with water. Bring to a simmer.

In a glass bowl, mix the egg whites and the sugar until combined.

Place the bowl on top of the simmering casserole, ensuring that the base of the bowl does not touch the water. Using a spatula, mix continuously until all the sugar dissolves or until the mixture reaches 70°C on a sugar thermometer.

Place the cooked egg whites and sugar in the bowl of an electric mixer fitted with a whisk attachment. Whisk until the bowl has cooled and the meringue is smooth and glossy. Add all the butter at this stage and whisk to combine.

Using a paddle attachment, add the lemon zest and mix on a low speed until smooth and glossy.

Once your cake is completely cooled, ice with buttercream.

Slice the cake in half and spread the centre with a good-quality raspberry jam. Sandwich the layers together before icing it with buttercream.