Simply mix all ingredients with a hand mixer. I always start with the liquid ingredients and then add the flour and baking powder at the end.
For me, this recipe is enough for around 13 waffles (thick heart waffles) - so a whole heart waffle only has around 120 kcal for me.
At my birthday brunch I offered these waffles and a conventional batter with a lot of butter and sugar and didn`t mention the fat difference. The vanilla quark batter was very popular and was eaten much faster than the normal batter. When I mentioned that there was neither butter nor sugar in the dough, everyone was very surprised and enthusiastic!