Preheat oven to 200 degrees Celsius/400 degrees Fahrenheit.
Wash cantaloupe well, then use a sharp knife to peel cantaloupe completely, taking off all rind and any bits of green flesh.
Cut melon in half.
Scoop out and discard seeds.
Chop cantaloupe into 1–2 inch-sized pieces.
Line a sheet pan with parchment paper, and spread out the melon pieces in a single layer.
Roast for 15-20 minutes until melon is soft and just beginning to brown.
Pour into large bowl, along with any syrup on the sheet pan, and use an immersion blender to purée.
Stir in olive oil and vermouth, and season to taste with salt (about ½ teaspoon).
Chill until cold.
To serve, sprinkle with lemon zest and piment d’espelette, then drizzle with balsamic vinegar.
Notes
Make-Ahead Instructions: This melon soup will keep for 2-3 days in the refrigerator. Wait until serving to add the lemon zest, piment d’espelette, and balsamic vinegar. Regular Blender Instructions: I love the ease of using an immersion blender for this recipe, because you don’t have to wait until the melon cools down before blending. However, you can absolutely use a regular blender instead. Just wait until the melon is warm before blending as hot blender contents can pop off the blender cap and potentially burn someone (or just make a huge mess!).