Preheat the oven to 180⁰C.

For convenience, take out and weigh all the ingredients (I cut the quantities in half here).

Melt chocolate and butter (use a bain-marie to avoid burning the chocolate).

In a second bowl, mix sugar and eggs together until creamy.

Add in the flour, mix until there are no clumps left (sieving the flour can help).

Finally, mix in the melted chocolate and butter. (Don't burn yourself with the hot bowl!)

Prepare a cake tin with some butter and flour to prevent the cake from sticking.

Pour the mixture in the tin, then bake in the oven for about 20 minutes. You might want to adjust the time depending on your oven and the desired texture. (Use a toothpick to check.)

Make sure you take the cake out of the oven once it's reached the desired texture.