Yes, I've made my own, but it takes time. If you need it today, you're out of luck. Prep time is only about 5 minutes. Standing time is in the "hours" category.
Start with 8 ounces of sour cream and 1 cup of whipping cream (not ultra-pasteurized). Whisk the two ingredients together in a medium mixing bowl. Cover with plastic wrap and let stand, at room temperature, for about 5 to 8 hours or until it thickens.
Once it's thickened, cover and chill in the refrigerator until serving time or up 48 hours. Stir before serving. This will yield about 2 cups.
"As a girl I had zero interest in the stove." - Julia Child
This is real inspiration. Look what Julia became!