Caramel M&M Cookies

Name: Caramel M&M Cookies
Prep time: 2 h 30 min
Total time: 2 h 30 min
Cuisine: American
Ingredients: 128 grams all purpose flour (1 cup; 4 1/2 ounces); 50 grams cocoa powder (1/2 cup; 1 3/4 ounces); 1/2 teaspoon baking soda; Pinch fine sea salt; 113 grams unsalted butter, softened (1/2 cup; 1 stick; 4 ounces); 70 grams granulated sugar (1/3 cup); 70 grams dark brown sugar (1/3 cup, lightly packed); 1 large egg, at room temperature; 1 teaspoon vanilla extract; 100 grams Caramel M&Ms, for tops of cookies (1/2 cup, or 4–5 M&Ms per cookie); Nonstick spray, for greasing tin; 160 milliliters whipping cream (2/3 cup); 45 grams unsalted butter, softened (3 tablespoons); 200 grams granulated sugar (1 cup); 60 milliliters water (1/4 cup); 20 grams corn syrup, or liquid glucose (1 tablespoon)