Grill the pineapple wedges over medium heat until browned on all sides, about 3 minutes per side. Let cool and then put in freezer for 30 minutes to chill.
Take two of the grilled pineapple wedges and cut each one into 4 pieces. Put the pineapple pieces on cocktail skewers with a maraschino cherry. Set aside to garnish the drinks.
Place the rest of the pineapple wedges in a blender and puree. Add the vodka, simple syrup, maraschino cherry juice, and vanilla. Blend. Add the egg whites and blend again. Let the mixture sit for a minute or two so that it separates into layers. Pour into chilled cocktail glasses (I like oversized martini glasses for this drink) either straight up or over ice. Spoon some of the foam on top of each drink and serve immediately.