Wash the peaches, grate them dry and cut them in half along the core. Remove seeds, cut peach halves into pieces and freeze for at least 3 hours.
Wash the lime hot, grate dry and finely grate the peel. Halve lime and squeeze juice. Wash lemon balm, shake dry and chop finely, except for a little to garnish. Mix agave syrup, chopped lemon balm, lime juice and zest with the peaches in a blender, except for some garnish.
Immediately cut out into 4 large balls and arrange in small bowls. Decorate with the rest of the lemon balm and lime powder.