Prepare the Brownie Base: In a large mixing bowl, combine the strawberry cake mix with 1/3 cup of oil and 2 eggs. Mix until well incorporated into a thick batter. Do not add water as you would for a regular cake, as this creates the dense brownie texture.
Bake the Brownies: Line an 8x8 inch baking pan with parchment paper for easy removal. Press the cake mixture evenly into the pan, smoothing the top with a spatula. Bake at 350°F (175°C) for 20 minutes. Remove from the oven and allow to cool completely. For faster cooling, place in the refrigerator.
Make the Frosting: In a medium bowl, mix together 3 oz of softened cream cheese and 1 cup of powdered sugar until smooth. Wash and hull 1-2 strawberries, then mash them thoroughly. Fold the mashed strawberries into the cream cheese mixture. For thicker frosting, use just 1 strawberry; for a thinner consistency, use 2 strawberries.
Frost the Brownies: Once the brownies are completely cooled, spread the strawberry cream cheese frosting evenly over the top. Place the frosted brownies in the refrigerator for at least 30 minutes to allow the frosting to set.
Slice and Serve: Remove the brownies from the refrigerator and lift them out of the pan using the parchment paper. Cut into squares and enjoy these delicious strawberry treats!