Start by heating your oven to 350°F (175°C). Grease the bottom of a deep 9x11-inch baking dish with butter.

In a mixing bowl, combine the brownie mix, 2 eggs, the canola oil, and water. Beat these ingredients together until the mixture is smooth and well combined.

Pour the brownie batter into the greased baking dish, smoothing it out to create an even layer.

In another bowl, begin whipping the cream cheese until smooth. Add the remaining egg and beat until the mixture is fully integrated. Gradually add the powdered sugar, continuing to mix until everything is thoroughly incorporated.

Dollop alternating spoonfuls of cherry pie filling and the cheesecake mixture over the brownie base. Use a butter knife to gently swirl the mixtures together, creating a marbled effect.

Place the dish in the oven and bake for 40 minutes, or until the top is slightly golden and the center is set.

Cool and Serve: Allow the brownies to cool in the pan before cutting them into squares. Serve each square with a spoonful of the remaining cherry pie filling and a dollop of whipped cream, if using.