Preheat the oven to 200 ° (convection: 180 °). Beat eggs, sugar and oil until foamy, add flour, baking powder and eggnog and mix into a smooth batter. Place in a baking dish (approx. 35 x 25 cm) lined with baking paper or on a baking sheet (then the pieces of cake will not be so high). Place in the preheated oven and bake for about 15 minutes (depending on the filling level) on the middle rack, until the cake has a nice light brown color and the dough no longer sticks to a wooden test stick.
Variations: Fold chocolate pieces, crumble or a couple of spoons of cocoa powder (baking cocoa) into the dough or after 5-10 minutes of baking (if the dough is slightly hardened) sprinkle with any decoration (e.g. mini smarties, crumble). Alternatively, couverture can of course also be poured over the cake after baking.
Cut into 24 even pieces, preferably when the cake is still slightly warm and let cool down well. You can take the cake with you to a picnic as a kind of brownie. The cake can easily be kept in a closed can for 2 days without losing its juiciness.