In a small bowl, add in the graham cracker crumbs, sugar, and melted butter. Stir to combine. Divide the crumbs into four glasses. Tap the glass to even out the crumbs.
In a blender, add in the cream cheese and maraschino cherries. Blend until mostly smooth. You'll have to stop the blender and push the cream cheese and cherries around. It won't be completely smooth yet.
Add the granulated sugar, sour cream and key lime juice into the blender. Blend until completely smooth. Stop and stir. Blend again to make sure everything is blended and smooth.
In a large bowl, whip up the 1 and 1/2 cups of heavy cream until it reaches stiff peaks.
Pour the cherry limeade into the whipped cream and whip with the hand mixer until blended. It will be semi-thick, but pourable.
Pour the filling into the 4 cups. Tap to smooth the filling out.
Place into the fridge until chilled. I left mine overnight. Top with a dab of whipped cream and a maraschino cherry.