Heat oven to 325°F. Lightly grease 9-inch round cake pan.
Base: Stir together water, oil, egg and brownie mix until blended. Spoon batter into pan and spread evenly.
Bake 48-52 minutes. Cool completely in pan. Remove brownie from pan by running knife around edge of pan to loosen, inverting pan and tapping gently on counter.
Frosting: Using an electric mixer, cream butter and cream cheese until smooth. Add jam and vanilla extract and beat until combined.
Gradually add in powdered sugar while mixing and beat until fluffy and spreadable.
Frost cooled based and garnish lavishly with fresh berries and mint springs.