Preheat oven to 350°F (175°C). Line a 9x9-inch pan with parchment, leaving overhang for easy lifting.

In a microwave-safe bowl, melt 1/2 cup (1 stick) unsalted butter. Whisk in 1/4 cup neutral oil and 1 cup granulated sugar until glossy.

Whisk in 2 large eggs and 2 teaspoons vanilla until the mixture thickens slightly.

Sift in 3/4 cup Hershey cocoa powder, 3/4 cup all-purpose flour, and 1/2 teaspoon kosher salt. Fold gently until just combined. For extra richness, fold in 1/2 cup chocolate chips.

Spread batter evenly in the pan. Bake 18–22 minutes, until the center is just set and a toothpick comes out with moist crumbs.

Cool in the pan for 20–30 minutes. Lift out, slice cleanly with a warm knife, and serve.

In a small saucepan, whisk together 3 tablespoons Hershey cocoa powder, 3 tablespoons granulated sugar, and a pinch of salt.

Whisk in 2 tablespoons hot water to form a smooth paste. Cook over medium heat for 30–45 seconds to bloom the cocoa.

Gradually whisk in 1 3/4 cups milk. Heat until steaming, not boiling.

Remove from heat and stir in 1/2 teaspoon vanilla. Taste and adjust sweetness.

Top with marshmallows or whipped cream if you like.

Beat 1 cup (2 sticks) unsalted butter, room temp until creamy, 2 minutes.

Sift together 2 1/2 cups confectioners’ sugar and 3/4 cup Hershey cocoa powder to remove lumps.

With the mixer on low, add the sugar-cocoa mix gradually. Add a pinch of salt.

Beat in 2–4 tablespoons milk or heavy cream until fluffy and spreadable. Finish with 1 teaspoon vanilla.

Whip on medium-high 1 minute for extra lightness.