To make enough marshmallows to go with the cookie recipe, make this recipe twice, in two separate batches, repeating steps 1 through 5.
Mix cornstarch with confectioners' sugar in a small bowl. Coat two rimless baking sheets with cooking spray. Cut parchment to fit pans, draw 1 1/4-inch circles, and place on baking sheets, ink side down; spray with cooking spray. Dust with cornstarch mixture to cover completely; shake off excess. Sprinkle gelatin over the 1/3 cup cold water in a mixer bowl. Let stand to soften, about 5 minutes.
Heat remaining 1/4 cup water and the granulated sugar in a small pan over medium-high heat, stirring, until dissolved. Place a candy thermometer into syrup; wipe sides of pan with a wet pastry brush if crystals have splattered up. Boil, without stirring, until temperature reaches the soft-ball stage (238 degrees). Remove from heat; add to softened gelatin. Hand-stir with the whisk attachment a few seconds to cool; place bowl on mixer stand. Whisk on medium-high until soft peaks form and mixture holds a shape, 8 to 10 minutes.
Whisk in the vanilla and a small drop of red food coloring (for pale pink). Transfer half the mixture to a pastry bag with a 1/2-inch tip (such as Ateco #806), and pipe kisses inside circles on baking sheets.
Add another drop of food coloring to the mixture in the bowl, return to mixer, and whisk to blend. Transfer marshmallow mixture to the pastry bag, and pipe remaining kisses.
Let stand at room temperature until set, about 4 hours. Store in an airtight container at room temperature up to 2 days.
To assemble, place a small dab of melted chocolate on each cookie, and top with a kiss. Let stand to harden. Store airtight at room temperature up to 1 day. Serve at room temperature.