Add the raspberries*, tequila, Grand Marnier, sweet & sour mix, and ice** to a blender.
Cover and blend until smooth. Taste for any adjustments.***
Pour evenly between two margarita glasses. Garnish with a lime slice on the rim of each glass and a cocktail pick with two raspberries. Serve immediately.
Notes
*To remove the seeds, start by blending the raspberries alone. Then, pour the puree through a mesh sieve and add it back into the blender. At this time, add your remaining ingredients. **If using fresh raspberries, add 1 cup of ice. If using frozen berries, add ½ cup of ice.*** If the margarita is too tart, add 1-2 teaspoons of agave or simple syrup to adjust the sweetness and blend again. Add more ice as needed to thicken the margarita. If it becomes too thick, add a splash of sweet and sour mix to thin it out.