Allow the mascarpone or cream cheese to soften at room temperature for 30 minutes. Do not allow the mascarpone to soften too much, as it can separate at high temperatures.

Prepare the berry sauce first and allow it to cool before using in this recipe. A hot berry sauce will cause the whipped cream to melt. Combine the raspberries (or other berries) and sugar in a small saucepan. Use a spoon to crush the berries; if using strawberries, dice them before cooking. Bring the berries to a simmer over medium-high heat and simmer for 4 to 5 minutes, until the berries are falling apart. Pour the resulting sauce into a fine mesh strainer arranged over a bowl. Use the back of a large spoon to press the sauce through the strainer, discarding any seeds and pulp. Allow the sauce to cool in the refrigerator.

Next, prepare the whipped cream. Pour the chilled cream into a stand mixer bowl and add the confectioner's sugar. Whisk on medium speed first for a few minutes, then turn the speed up and whisk for about 3 to 4 minutes until stiff peaks form. Set aside.

In a separate mixing bowl, beat the softened cream cheese or mascarpone for a few minutes until it's smooth and creamy. Melt the white chocolate in the microwave or over a double boiler. Do not let the chocolate cool!! Add the warm, melted white chocolate, vanilla and salt to the cheese. Mix again for a few minutes until well combined. Add the berry sauce last, along with red food coloring if desired. Beat again until the sauce is well-incorporated and the mixture is smooth.

Add the cheese and berry mixture to the whipped cream. Whisk the frosting on medium speed for 30 seconds, then stop and scrape down the sides of the mixing bowl. Mix again for up to 30 seconds, until stiff peaks form. Use the frosting right away, or keep refrigerated.

NOTE: if using berry preserves, substitute the fruit and sugar with ½ cup preserves.