Quark is a wonderful ingredient for quick baking because it adds a moist texture and pleasant flavor.
Beat the sugar and oil for a few minutes, then add the eggs, Quark, and vanilla and mix until well blended.
Whisk together the flour, baking powder, baking soda, and salt.
Add the dry ingredients to the wet ingredients all at once and mix just until all the flour is incorporated but don’t over-mix. Fold in the walnuts if desired.
Scoop the batter into a loaf pan or mini loaf pan. This batter makes one normal size loaf, or 8 mini loaves.
Bake at 350 for 50 to 60 minutes for a full-size loaf or 25 to 30 minutes for mini loaves.
Serve warm! Here’s a printable version