2/3 cup packed dark brown sugar

1 teaspoon vanilla extract

Arrange a rack in the middle of the oven and heat to 325 F. Coat a 9-inch square baking pan with cooking spray and dust with flour, tapping out the excess; set aside.

Place the oil into a microwave-safe medium bowl and heat on low power in four to six 5-second bursts until it is warm but not hot. Add the cocoa powder, and whisk until completely smooth and combined. Let sit for 4 or 5 minutes so the cocoa can bloom. Meanwhile, prepare the dry and wet ingredients.

Place the flour, baking powder, and salt in a small bowl and whisk to combine; set aside.

Place the eggs, powdered sugar, and brown sugar in a large bowl. (Alternatively, place in the bowl of a stand mixer fitted with the paddle attachment.) Beat on medium speed until fluffy and lighter in color, 2 1/2 to 3 minutes. Beat in the vanilla until just combined.

Add 1/2 of the cocoa mixture to the egg mixture, and mix at medium-high speed until it is shiny and fully combined, about 5 minutes.

Add the flour mixture to the egg and cocoa mixture, and mix at low speed until fully combined. Add the remaining cocoa mixture, and mix at medium-high speed until the batter is shiny and fully combined, about 1 minute. Transfer to the baking pan.

Bake for 20 to 24 minutes. You can allow it to bake for up to 30 minutes if you like a firmer brownie with some crisp edges. The brownies will pull away from the edges of the pan, but a cake tester or knife inserted in the middle will not come out clean. Let cool before cutting into 16 small squares.

Recipe notes: These will keep in a closed container or wrapped in plastic at room temperature for up to two days.

(Tami Weiser is a contributor to TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to editorial@thekitchn.com.)