Blackberry Mousse Cake - Oregon Raspberries & Blackberries

Ingredients

• 3/4 cup good quality white chocolate chips (135g)
• 1 cup heavy cream or heavy whipping cream, cold - divided (240g)
• 1/3 cup seedless Oregon blackberry jam (75g)
• Purple gel food coloring - optional
• 1/3 cup powdered sugar (42g)
• 1 teaspoon vanilla extract (4g)
• ⅛ teaspoon fine salt
• 1 cup or 2 sticks unsalted butter, room temperature (226g)
• 2 ½ cups granulated sugar (500g)