Beat the butter until foamy. Gradually stir in sugar, salt, quark and lemon zest. Mix the flour & baking powder, sieve and mix in with the milk. Butter the loaf pan (or line it with baking paper) and pour in the batter.
Bake in the preheated oven at 200 ° C for approx. 60 minutes with top and bottom heat.
TIP: I took a little less sugar and instead added raisins to the dough and took a little more milk (approx. 200 ml).