Dutch stroopwafel

In a separate bowl, combine the all-purpose flour, softened unsalted butter, sugar, egg, and a pinch of salt. Pour in the activated yeast mixture and knead until you have a smooth, elastic dough.

Cover the bowl and let the dough rise in a warm spot for one hour, or until it has doubled in size.

While the dough is rising, prepare the stroop filling. In a saucepan, combine the Dutch stroop, brown sugar, unsalted butter, and cinnamon. Stir over medium heat until the butter melts and the sugar fully dissolves, creating a smooth, glossy syrup.

Let it simmer gently for a few minutes. The stroop will thicken considerably as it cools, so don't worry if it seems a little thin at this stage.