Combine 1 cup plain unsweetened almond milk, ½ cup granulated sugar, and ½ cup light brown or demerara sugar in a small saucepan and cook over medium heat, stirring constantly, until dissolved, about 3 minutes. Do not let boil. Remove from heat and stir in ¼ tsp. almond extract, ¼ tsp. orange flower water, ¼ tsp. rose water, and 1 tsp. orange curaçao, if using. Let cool 5 minutes, then pour into a resealable jar or swing-top bottle and refrigerate until chilled. Do ahead: Orgeat can be made 2 weeks ahead; keep chilled. Shake before using.
