Start by preparing the berry sauces. In a medium saucepan over medium heat, combine chopped strawberries, raspberries, and blueberries with sugar. Stir gently until the berries begin to break down and the mixture thickens slightly, about 10-12 minutes. Once ready, transfer the berry sauces to a bowl and let them cool to room temperature.

Next, make the creamy cheesecake filling. In a large mixing bowl, beat the softened cream cheese using an electric mixer until it's smooth and creamy, approximately 2-3 minutes. Gradually add in the heavy whipping cream and powdered sugar, mixing on medium speed until the mixture becomes light and fluffy, around 4-5 minutes.

Now it's time to poke the cake! Use a wooden spoon handle or another similar object to carefully poke holes evenly spaced throughout the baked cake. Make sure to poke deep enough to allow the berry sauce to seep through.

Fill those holes with the cooled berry sauces. Using a spoon, carefully dollop the strawberry, raspberry, and blueberry sauces into the holes, allowing the flavors to soak in. Spread the cheesecake filling over the top of the cake and then top with whipped cream.

Chill the Summer Berry Poke Cake in the refrigerator for at least 4 hours, or ideally overnight. When ready to serve, slice the cake and enjoy.