Preheat the oven to 350°F (175°C). Line two large baking sheets with parchment paper. Unwrap the caramels and set them aside.

In a large bowl with a hand mixer, or in a stand mixer with the paddle attachment, cream the softened butter, brown sugar and granulated sugar on medium speed until light and fluffy, about 2 to 3 minutes. Add the eggs and vanilla and mix on low speed for 1 to 2 minutes, until well combined.

In a medium bowl, whisk together the flour, baking powder, baking soda, corn starch, salt and cinnamon.

With the mixer running on low, add the dry ingredients a little at a time and mix just until combined. Stir in the crushed pretzels by hand.

Scoop about 3 tablespoons of dough (a heaping 2-tablespoon scoop) and flatten it in your palm. Set a caramel in the center, then wrap the dough around it and pinch it closed so the caramel is completely sealed inside. Roll it into a ball and place it on a baking sheet. Repeat with the remaining dough and caramels to make 24 cookies, spacing them about 2 inches apart.

Press a few extra pretzel pieces into the tops of the cookies if you like, and sprinkle each one with a pinch of flaky sea salt.

Bake for 10 to 12 minutes, until the edges are lightly golden and the centers still look a little soft.

Let the cookies cool on the baking sheet for 5 minutes (the caramel is very hot), then move them to a wire rack to finish cooling.