For the blackened butter: Combine everything but the butter in a small bowl and mix until well blended.
Add 1 1/2 teaspoons of the spice mixture to the softened butter and blend completely. (Reserve the remaining spice mixture for another use.)
Lay a piece of plastic wrap on a work surface. Place the spiced butter on the lower third of the plastic in a 2- to 3-inch-wide oblong shape. Gently wrap the shorter end of the plastic up and over the butter, using it to help shape and roll the butter into a log. Twist the ends of the plastic closed, like a hard-candy wrapper. Chill until firm, at least 30 minutes, preferably 1 hour. (Makes 1/2 cup.)
For the cheesy grits: Combine the milk, 3/4 cup water, cream and salt in a medium saucepan over medium heat. Bring to a boil and slowly whisk in the grits, making sure there are no lumps. Reduce the heat to low, cover and cook, stirring occasionally, until thickened and soft, about 8 minutes. Remove from the heat, add the Muenster and Parmesan and stir until blended.
Top each serving with 1 tablespoon of the blackened butter.