01 - Combine the diced pineapple, sliced peaches, cold water, and lime juice in a blender. Blend on high until completely smooth, about 1-2 minutes.
02 - Taste the mixture and add agave syrup or sugar as desired. Blend briefly for 10-15 seconds to incorporate the sweetener.
03 - Pour the blended mixture through a fine mesh strainer into a large pitcher. Press firmly with a spatula to extract as much liquid as possible. Discard the pulp or reserve for smoothies.
04 - Refrigerate the agua fresca for at least 30 minutes to allow flavors to meld. Serve over ice cubes and garnish with fresh mint leaves and fruit slices if desired.