In a small bowl, dissolve the active dry yeast in the warm milk. Let it sit for 5 minutes until frothy and active.

In a large mixing bowl, combine the melted butter, granulated sugar, and egg. Stir in the yeast mixture until well incorporated.

Gradually add the flour, ground cinnamon, and chopped pecans to the wet ingredients. Knead gently until a smooth dough forms, then cover the bowl with a towel and let it rest for 30 minutes.

While the dough rests, prepare the filling. In a medium saucepan, whisk together the dark brown sugar, butter, and heavy cream over medium heat.

Boil the caramel gently for 5 minutes, stirring constantly until it thickens slightly. Remove from heat, stir in the flaky sea salt, and set aside to cool and thicken.

Preheat your stroopwafel maker or pizzelle iron. Divide the rested dough into 8 equal portions and roll them into smooth balls.

Place one dough ball onto the center of the hot iron and press down firmly. Cook for 1 to 2 minutes, or until the waffle is golden brown and crispy.

Immediately remove the warm waffle. While it is still hot and pliable, use a round cookie cutter to trim the edges neatly, then use a sharp, thin knife to carefully slice it horizontally into two thin halves.

Spread a generous tablespoon of the salted caramel filling onto one half, then press the second half on top to sandwich them together. Repeat the cooking and filling process with the remaining dough.

Allow the stroopwafels to cool flat on a wire rack until the caramel sets. Serve by resting one over a hot cup of tea or coffee for a minute to warm the center before enjoying.