1 portion of walnut muffin batter
Prepare the batter according to the instructions given here.
You can also use hazelnuts instead of walnuts.
Butter a rectangular cake pan and pour the batter in. Smooth the surface of the batter and bake at 175 °C for 20 - 30 minutes, or until a cake tester/toothpick inserted in the cake comes out clean. If the surface seems to brown too much, cover it with foil towards the end of baking.
Let the cake cool for a couple of minutes in the pan. Remove the cake from the pan and let it cool completely on a wire rack. Serve the cake with coffee or tea. Store it in a plastic bag or wrapped in wax paper.
You may use this same batter to prepare walnut muffins.
Recipe source: adapted from "Pähkinämuffinsit", Ihatsu, A. et al., ed. (1993) Otavan suuri keittokirja. Keuruu: Otava.