Preheat the oven 325 degrees F. Prepare a 9-inch round cake tin by buttering and then lightly dusting with flour. (Alternatively, you can line the base of your cake dish with parchment paper.)

Making the sponge cake

1. In a saucepan over low heat, melt the butter. Then add milk and lemon juice to the melted butter. Set aside to cool.
2. In the bowl of a stand mixer, whisk eggs and sugar until pale and thickened, about 5 minutes.
3. Prepare dry ingredients separately in a medium bowl by sifting together the flour and baking powder. Add lemon zest and mix gently. Using a wooden spoon or rubber spatula, gently fold about a third of the flour mixture into the egg mixture – be careful not to mix too hard otherwise you may mix away some of the air bubbles present in the egg mixture. Follow this by gently folding in about half the set aside butter mixture, followed by another third of the flour mixture. Repeat once more to fold in the remaining butter mixture, and then flour mixture.
4. Pour your cake batter into the prepared cake tin, and bake in the centre of your oven for 25 minutes. Remove from the oven, but do not turn it off, instead set it to preheat for 365 degrees F.

Making the tosca topping

Begin by melting the butter in a saucepan over medium heat, add the flour and mix. Add sugar, cream, salt, and flaked almonds, gently stir until thickened, 1-2 minutes. (Don’t do this too early. You want the caramelized almond mixture to still be hot for the next stage!)

Making the toscakaka

1. Preheat the oven to 365 degrees F.
2. Gently spoon the still-hot caramel almond mixture (tosca topping) over the top of the cake. Place the cake back into the centre of the oven, and bake for another 10-12 minutes, or until cooked through.
3. Allow the baked toscakaka to cool for 25-30 minutes before removing it from the cake tin. Cut with a warm knife, serve alongside cream or yogurt.