2/3cup(70g) unsweetened cocoa powder, plus more for pan
1cup(200g) granulated sugar
3/4cup(160g) packed light-brown sugar
1/2cup(113g) unsalted butter, melted
1/4cup(60ml) vegetable or canola oil
1/3cup(60g) mini semi-sweet chocolate chips
Frosting and fruit
6oz. cream cheese, softened
1cup(120g) powdered sugar
Fresh fruit of various colors for topping(recommended are strawberries, raspberries, kiwi, blueberries, blackberries, bananas)
Preheat oven to 325 degrees. Butter a deep dish 12-inch pizza pan (be sure it's at least 3/4-inch deep) or a 12-inch cake pan then line with a round of parchment paper on bottom, butter parchment and dust pan with 1 tsp cocoa powder. Set aside. In a mixing bowl whisk together flour, cocoa powder, cornstarch and salt. Set aside.
In a large mixing bowl stir together granulated sugar, brown sugar, melted butter and vegetable oil. Blend in eggs one at a time while adding in vanilla with the last egg. Add in flour mixture and mix just until combined then mix in chocolate chips. Pour batter into prepared pan and spread into an even layer, then wiggle pan to level. Bake in preheated oven until toothpick inserted into center comes out free of batter about 18 - 22 minutes. Remove from oven and set on a wire rack to cool completely.
For the frosting:
In a mixing bowl, using an electric hand mixer, blend together cream cheese, powdered sugar and vanilla until smooth and slightly fluffy. Spread over cooled brownies, cover and transfer to fridge and chill for at least 30 minutes (or up to 1 day). Add fruit just before serving (because the fruit will begin to break down and make the topping runny) then if desired warm 2 Tbsp apple jelly, whisk to smooth and spread over fruit with a pastry brush. Cut into slices and serve immediately for best results.