Preheat oven to 325 degrees. Lightly spray 48 mini muffin cups with non-stick cooking spray. Pat the maraschino cherries dry with paper towels. In the bowl of a food processor, combine the 1 cup of butter and cream cheese and process until blended. Add the flour and 1/8 tsp. salt to the processor and blend until mixed. Do not over-process. Using a small ice cream scoop or spoon, scoop out about 1 Tbsp. of dough per cookie and roll into balls. Place the balls into the prepared muffin tins. Using your thumb or the end of a French rolling pin, make an indentation in each ball. In a small bowl, whisk together the 2 Tbsp. reserved maraschino cherry juice, 1 Tbsp. melted butter, remaining 1/8 tsp. salt, sugar, egg, and vanilla extract. Put about 3/4 tsp. of the mixture into each dough ball indentation. Place a maraschino cherry in each cookie with the stem up. Bake for 25 minutes or until cookies are lightly browned and the filling is set. Let cool in the pans for 5 minutes and then remove to a wire rack to finish cooling. Makes 48 cookies.