Easy Chocolate Souffle

Name: Easy Chocolate Souffle
Ingredients: 1/2 cup of chopped room temperature chocolate or chocolate chips (dark, semi-sweet, milk, etc.(60g)); 1 tbsp butter (salted or unsalted (14g)); 1 tbsp all-purpose/plain flour (8g); 1/3 cup cold milk (whole, 2%, etc. (80ml)); Pinch of salt; 1 large egg yolk (room temperature); 2 room temperature egg whites from large eggs; 1/4 tsp. of cream of tartar (1g); 2 tbsp white granulated sugar (25g); Powdered sugar for topping; Butter and sugar for the ramekins