1-1/2 cups sugar
1 cup full-fat buttermilk
1/2 cup packed light brown sugar
1/2 cup light corn syrup
1 teaspoon baking soda
1/2 cup butter
2 Tablespoons Kahlua
1 teaspoon vanilla extract
Add cashews to a large nonstick skillet and toast over low heat just until fragrant. Set aside. Prepare two baking sheets by lining with parchment paper. A marble slab also works well, no parchment needed. Grease the sides of a large heavy-bottomed pot (I use my 7 quart Dutch oven) with butter. Add and combine sugar, buttermilk, brown sugar, corn syrup and baking soda over medium heat. Insert candy thermometer and bring mixture to a boil, stir gently and continuously until soft ball stage of 235 degrees F is reached. (I would suggest wearing long sleeves and an oven glove to prevent any burns from the sugar mixture.) Remove from heat and stir in butter, Kahlua and vanilla (it will sputter a bit). When butter is melted let mixture stand anywhere from 3-20 minutes (depending on humidity in your area) until mixture is a thik caramel. Stir in cashews with a wooden spoon until the mixture no longer looks glossy. Spoon mounds onto prepared baking sheets, using two spoons. Allow to set about 30-45 minutes. If mixture seems really thick, add a little bit of hot water to make the mixture stir-able again. Keep for two weeks in a sealed container. Store between sheets of waxed paper.