Turn the oven to 180C (200c if not fan)
Melt the butter and then add the chocolate – and set aside.
In a stand mixer, whisk the egg and sugar until pale and fluffy.
Mix the dry ingredients together.
Sift the dry ingredients into the egg and sugar mixture and then fold in the butter and chocolate mixture.
Using a spatula, add to the baking tin and place in the pre-heated oven for 14-15 minutes.
Baking time of kladdkakor really varies – you don’t want the middle to be baked through, but you do want the cake to hold. Using a tooth pick, test the edge of the cake – if it comes out clear about 2 cm in and the cake does not look TOO runny in the middle, take it out. If you feel it needs a bit more, simply leave it to cool in the tin (but if you feel it may have had 30 seconds too much, remove from the tin immediately to stop the baking.
Once you know how your oven react and bake it, you will know the perfect length to bake it going forward.