Combine 1 cup cream with 2 tbsp buttermilk in a 500-mL Mason jar. Cover with cheesecloth and secure with a rubber band. Leave on counter at room temperature until very thick, 8 to 24 hrs. Cover and refrigerate up to 10 days.
Quick fruit parfaits
Whip cream to soft peaks, then beat in a bit of sugar until stiff peaks form. Layer in martini glasses with cubed pound cake, sliced strawberries and chocolate chips.