Heat your oven to 170°F.Pour the cream into a deep casserole dish that has a cover that can go into the oven. You’re aiming for a deep dish so that the cream is about 2 to 2.5 inches deep when poured in. I used a casserole dish with a glass cover, kind of like an old school pyrex type thing. Cover the dish and place in the 170°F oven for 10 to 12 hours, or overnight, which is what I did.The next day (or 10 to 12 hours later), remove the casserole from the oven and let cool to room temperature before placing in the fridge for a minimum of 8 hours, or overnight.Skim off the top, slightly golden, thickened layer. This is your clotted cream! There will be another layer under the slightly yellow layer that is creamy and thick like sour cream – this is clotted as well, but with a bit more moisture in it. Skim that off as well. Use a stand or hand mixer and whip up the the two kinds of cream until thick. Serve chilled and enjoy! I love it on scones, toast (SO GOOD), cake, basically anything or everything!The clotted cream should keep in the fridge for up to 5 days, covered.