For Melon Jelly: In the container of a blender, place all melons, mint, and lemon juice; blend until smooth. Strain mixture into a medium saucepan, reserving ¼ cup melon juice; discard solids. Add brown sugar to saucepan; bring to a boil over medium heat.
In a small bowl, whisk together reserved ¼ cup melon juice and cornstarch. Whisk cornstarch mixture into juice mixture; cook, stirring constantly, until mixture has thickened, 2 to 3 minutes. Transfer to a heatproof bowl, and let cool. Cover with a piece of plastic wrap, pressing wrap directly onto surface to prevent skin from forming. Refrigerate for at least 1 hour.
For Whipped Cream: In the bowl of a stand mixer fitted with the whisk attachment, beat cream, confectioners’ sugar, and vanilla at medium speed until mixture has thickened and soft peaks form. Add mascarpone; beat until combined, about 3 minutes.
Layer 3 tablespoons Hazelnut Granola, whipped cream, and melon jelly in serving glasses. Top with additional granola.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/melon-trifles-2/