Red Velvet Nutella Cookie Sandwiches

Name: Red Velvet Nutella Cookie Sandwiches
Cook time: 2 h 24 min
Total time: 2 h 24 min
Cuisine: American
Ingredients: 2 1/2 C all-purpose flour; 1 1/4 tsp baking soda; 1/2 lb unsalted butter (melted); 1 1/2 C packed dark brown sugar; 1/2 C granulated sugar; 1 tbsp liquid red food dye; 1 large egg; 1 egg yolk; 2 tsp vanilla extract; 1 tbsp plain Greek yogurt (can sub sour cream); 1 C semi-sweet mini (or regular) chocolate chips; 500g jar of Nutella, chilled in refrigerator; Coarse sea salt, for sprinkling; Cream cheese frosting (optional)