In a large bowl, mix the flour, sugar, salt, and ground cinnamon. Add the butter and use your fingers or a pastry cutter to blend until the mixture resembles coarse crumbs.
In a separate bowl, whisk the egg and milk together. Gradually add this to the flour mixture, mixing until a dough forms. Knead the dough lightly until smooth. Wrap it in plastic wrap and let it rest for 30 minutes.
In a medium saucepan over medium heat, combine the brown sugar, butter, corn syrup (or honey), and cinnamon. Cook, stirring constantly, until the mixture comes to a boil and the sugar has dissolved.
Reduce the heat and simmer for 2-3 minutes, until the mixture thickens slightly. Remove from heat and let it cool slightly.
Preheat a waffle iron according to the manufacturer’s instructions. Divide the dough into small balls (about 1 tablespoon each) and flatten them into thin discs.
Place a disc of dough onto the hot waffle iron and cook until golden brown and crisp, about 1-2 minutes. Remove the wafel and immediately cut it in half while still warm.
Spread a layer of caramel filling on one half of each wafel. Top with another wafel half to make a sandwich. Press gently to spread the filling evenly.
Let the stroopwafels cool completely before serving. They are delicious on their own or can be enjoyed with a hot beverage.
Enjoy your meal!