Add all ingredients to shaker tin and shake for 5 seconds without ice to emulsify. Add ice and continue to shake. The goal is to create a meringue-like texture, so long shakes for 30 to 60 seconds are ideal. Double strain into a flute glass.Butternut squash purée1 butternut squashPreheat oven to 400 degrees. Halve butternut squash and remove seeds. Roast until squash is tender and easily pierced with a fork, about 30 minutes. Remove meat and puree.Tarragon syrup2 cups sugar1 cup waterSprigs of tarragonIn a medium pot over medium heat, combine water and sugar. Add tarragon and simmer until desired flavor is reached. Strain out sprigs.