Combine sugar and water in a small saucepan over medium heat. Stir until the sugar dissolves completely.
Remove from heat, stir in vanilla paste or extract, and let cool to room temperature. Store in an airtight container in the refrigerator for up to 2 weeks.
Peach margarita
Mix chili lime salt or tajín on a small plate. Moisten the rim of a margarita glass with a lime wedge, then dip it into the salt mixture to coat.
In a blender, combine tequila, triple sec, lime juice, vanilla simple syrup, peach cubes and 1 cup ice. Blend until smooth. Add more ice if needed for a thicker texture.
Pour the margarita into the prepared glass and garnish with a lime wheel.