Part 5/7:
- Berry Filling: In a medium bowl, combine the blueberries, raspberries, strawberries, and lemon zest and juice. Toss gently and set aside.
Making the Frosting
Cream Cheese and Mascarpone: In a stand mixer fitted with the paddle attachment, combine the cream cheese and mascarpone. Mix on medium until well combined.
Add Sugar: Gradually add the powdered sugar while mixing on low speed. Scrape the bowl down and mix on medium speed until smooth.
Whipped Cream: In a separate bowl, whip the chilled heavy cream and vanilla until stiff peaks form.
Combine Mixtures: Gently fold the whipped cream into the mascarpone mixture until just combined. Taste to ensure it meets your sweetness preference.