In Sweden, chocolate mud cake is called kladdkaka. This word can be literally translated from Swedish as “gooey cake”. It is a brownie-like cake with dense and sticky texture and a soft and gooey center. Chocolate mud cake is usually served with whipped cream, a scoop of vanilla ice cream, or fresh strawberries.

There are many different chocolate mud cake recipes, but they have one thing in common: the pastry is never made with baking soda or other leavening agents. The lack of gas bubbles produced by the use of leavening agents provides for the dense texture of the cake. Common ingredients of the cake include butter, sugar, flour, eggs, cocoa powder, and chocolate (optional). Ground nuts and various spices such as vanilla or cardamom can be added, too. https://en.wikipedia.org/wiki/Kladdkaka