In a small saucepan, combine the pumpkin butter, sugar, cinnamon, and 1 cup of water. Bring to a simmer and heat gently for 10-12 minutes until the syrup thickens and the granules dissolve. Pull the pan from the heat and whisk in the vanilla extract. Let cool. Leftover syrup keeps for up to 2 weeks in the fridge.
In a shaker, combine the tequila, syrup, lemon juice, and egg white. Dry shake for 45 seconds, then add ice and shake 20-30 seconds longer. There should be a bubbly layer of foam atop.
Pour into a coupe glass and garnish with a few shakes of cinnamon or pumpkin spice topping. Cheers!