Shake all ingredients except Topo “dry” to emulsify before adding ice. Add ice & shake again until chilled. Strain into cocktail glass. Top with splash of Topo Chico. Can also be made without the Topo Chico and/or egg white.
Add Pisco, lime juice, syrup, & egg white to shaker. Dry shake (without ice) vigorously for 30 seconds. Add ice & shake again. Strain into coupe glass. Spray or dot Angostura bitters on top as artistically as desired!