1Pour the heavy cream into a stand mixer or food processor.
2Whip on medium-high speed until the cream passes the whipped cream stage and begins to separate into butter solids and buttermilk. This usually takes 8-12 minutes.
3Once separated, pour off the liquid (buttermilk). You can save this for baking or pancakes.
4Transfer the butter solids to a bowl.
5Pour cold water over the butter and knead or press with a spatula to wash out excess buttermilk.
6Drain and repeat with fresh cold water until the water runs mostly clear.
7Place the washed butter back into the mixer/processor.
8Add 2 teaspoons of salt and mix until evenly incorporated.
9Slowly drizzle in 1/4 cup of olive oil while mixing, until it blends smoothly into the butter.