Prepare the Dough:

1. In a small bowl, combine the warm milk and yeast. Stir gently and let it sit for 5-10 minutes until it becomes foamy. This proves your yeast is active—if it doesn’t foam, your yeast may be expired.
2. In a large mixing bowl, whisk together the flour, sugar, and salt. Create a well in the center of the dry ingredients.
3. Pour the activated yeast mixture, melted butter, egg, and vanilla extract into the well. Stir with a wooden spoon or spatula until a smooth, thick batter forms. The consistency should be similar to thick pancake batter, not a stiff cookie dough.
4. Cover the bowl with a clean kitchen towel or plastic wrap and let it rest in a warm spot for 30 minutes. The dough will become slightly puffy but won’t double in size like bread dough.

Make the Caramel Filling:

5. While the dough is rising, prepare your caramel filling. In a medium saucepan over medium heat, combine the brown sugar, butter, corn syrup, cinnamon, and salt.
6. Stir constantly with a wooden spoon until the butter melts and the sugar completely dissolves, about 3-4 minutes. The mixture should be smooth and glossy.
7. Bring the mixture to a gentle simmer and cook for 2-3 minutes, stirring frequently, until it thickens slightly. Don’t let it boil vigorously or it will become too hard when cooled.
8. Remove from heat and keep warm. The caramel should be spreadable but not runny. If it becomes too thick as it cools, you can gently reheat it.

Cook the Waffles:

9. Preheat your pizzelle maker or stroopwafel iron according to the manufacturer’s instructions. Most should be heated to medium-high heat.
10. Lightly grease the iron with cooking spray or brush with melted butter before the first waffle (you usually won’t need to grease it again after this).
11. Drop about 1 tablespoon of batter onto the center of the preheated iron. Close the lid and cook for 30-60 seconds, depending on your iron, until the waffle is golden brown. Watch carefully—they cook quickly!
12. Using a spatula, carefully remove the hot waffle and immediately place it on a cutting board.

Assemble the Stroopwafels:

13. This is the tricky part, but you’ll get the hang of it! While the waffle is still warm (work quickly!), use a sharp serrated knife to carefully slice it horizontally into two thin layers. Place the knife parallel to the cutting board and use a gentle sawing motion.
14. Spread about 1-2 teaspoons of the warm caramel filling onto one waffle half, then gently press the other half on top to create a sandwich. The warmth of the waffle will help the caramel spread and adhere.
15. Place the assembled stroopwafel on a wire rack to cool and set. As it cools, the caramel will firm up while the waffle becomes crispy.
16. Repeat with the remaining batter and caramel filling. Work in batches—it’s easier to cook a few waffles, slice and fill them while they’re warm, then cook the next batch.