from https://www.allrecipes.com/recipe/239478/grandmas-buttermilk-syrup/
1 cup white sugar
½ cup buttermilk
½ cup butter
1 teaspoon baking soda
1 teaspoon vanilla extract
Heat sugar, buttermilk, and butter in a saucepan over medium heat until the mixture starts to boil, about 5 minutes. Creamy buttermilk syrup in a saucepan with a whisk.
Remove the saucepan from heat and stir baking soda and vanilla into the buttermilk mixture.