Preheat oven to 350.
Grease a 9x13 pan and set aside.
Prepare brownie batter according to box directions.
Pour into prepared pan and bake for 20 minutes or until top appears completely set.
Remove from oven and allow to cool for 30 minutes.
Cream together cream cheese, sugar and eggs until well blended.
Spread cream cheese mixture evenly over brownie layer.
Bake for 35 - 40 minutes or until cheesecake layer is set.
Remove from oven and allow to cool at least 30 minutes until top is no longer warm to the touch.
Beat butter and strawberry preserves while slowly adding in powdered sugar.
Add in food colouring if using to achieve pink colour, then whip to get uniform colour.
Frost cheesecake layer by spreading frosting with a spatula to completely cover.
Refrigerate at least 2 hours before serving.