Add 1 cup of water to saucepan and heat over medium-high heat. Add in 1 tablespoon of gelatin, stirring well with a rubber spatula. Once gelatin is dissolved, add 1/4 cup of sugar. Continue to heat and stir to dissolve completely.
Add heavy cream and stir to combine. Pour into large container with a spout and pour evenly into 4 parfait cups, or small mason jars. Allow to set in the refrigerator for 1 hour.
Heat another 1 cup of water in the microwave until warm. Stir in instant coffee grounds until dissolved. Set aside.
Add remaining 1 cup of water to saucepan and heat over medium-high heat. Stir in remaining 2 tablespoons gelatin with a rubber spatula. Once dissolved, add 1/2 cup of sugar. Continue to heat and stir to dissolve completely. Add coffee and stir to combine.
Pour into large container with a spout and pour evenly into cups with the heavy cream layer. Coffee may start to dissolve cream layer a little, and that's okay. If this occurs, gently stir the coffee layer to combine the cream.
Allow gelatin to set completely in the refrigerator, about 2 hours. Top with whipped cream before serving.
Gelatin parfaits stay fresh in the refrigerator, covered, up to 1 week.