In a small pot over medium heat, melt butter and cook, stirring occasionally, until the butter foams and browns, about 2 minutes.
Add dates and ½ cup water and cook, undisturbed, until the dates soften, 1 to 2 minutes. Using a wooden spoon, mash the dates into a paste.
Add milk, oats, vanilla and cinnamon, and stir to combine. Bring to a simmer, then cook, stirring occasionally, until the oats are tender and the oatmeal has reached your desired consistency, 4 to 6 minutes.
Divide the oatmeal between bowls, sprinkle with flaky sea salt and serve with chopped fruit and a drizzle of cream, if desired.