Prep the pan and oven. Heat your oven to 350°F (175°C). Grease an 8-inch round cake pan and line the bottom with parchment for easy release.

Whisk dry ingredients. In a medium bowl, whisk the sugar and cocoa powder until no cocoa clumps remain. If using salt, whisk it in now.

Add the eggs. Crack in the eggs and whisk until the mixture looks thick, glossy, and smooth. Take 30–45 seconds to fully blend; this helps the cake set nicely.

Stream in the oil. Slowly whisk in the oil until the batter looks shiny and uniform. Oil keeps the crumb tender and moist.

Finish with milk. Pour in the milk (and vanilla if using) and whisk until just combined. Don’t overmix. The batter will be pourable and velvety.

Bake. Pour the batter into the prepared pan. Bake for 25–32 minutes, until the center springs back lightly and a toothpick comes out with a few moist crumbs.

Cool. Let the cake cool in the pan for 10 minutes, then turn out onto a rack and peel off the parchment. Cool another 20–30 minutes before slicing.

Serve. Dust with cocoa or powdered sugar, drizzle with warmed cream, or enjoy plain. It’s rich enough to stand alone.