Strain the mixture into a storage container, discarding any solids in the strainer. Whisk in the remaining 1 cup milk, the remaining 1 cup cream, vanilla extract, rums, brandy and bourbon. Refrigerate for several hours, until chilled, then store in the refrigerator for up to 1 week.
Note: Horchata is a traditional refresher in Spain and Latin America, typically made with almonds and rice or other grains. Here, it is combined with an aged, spice-infused tequila for a spicy, warming (and vegan) eggnog substitute. It can be served warm or cold. The horchata mixture needs to be refrigerated/chilled for at least 8 hours and up to overnight. You'll have turbinado syrup left over; it can be refrigerated for up to 2 weeks. Toast the almonds in a small, dry skillet over medium-low heat, shaking the pan as needed to prevent scorching, until the nuts are fragrant and lightly browned. Cool completely before using. To make turbinado syrup, combine 1 cup turbinado sugar with 1/2 cup water in a pan, and heat gently over medium-low heat, stirring until the sugar has dissolved. Cook for a few minutes; cool completely before using. Adapted from Brook Vandecar of Rosa Mexicano.
• 500 milliliters (about 2 c.) añejo tequila or reposado tequila, such as Herradura añejo
• 2 c. uncooked long-grain brown rice, ground to powder in a spice grinder