Step 1: Prepare the Raspberry Sauce. In a small saucepan, combine 1 cup of raspberries, granulated sugar, and lemon juice. Cook over medium heat, stirring occasionally, until raspberries break down and the sauce thickens slightly, about 5-7 minutes. Remove from heat and let cool completely. Once cool, gently mash with a fork or process briefly in a food processor for a smoother sauce (optional).
Step 2: Prepare the Mascarpone Cream. In a large mixing bowl, combine the softened mascarpone cheese, cold heavy cream, powdered sugar, and vanilla extract. Beat with an electric mixer on medium-high speed until light, fluffy, and stiff peaks form. Be careful not to overbeat, or it might curdle.
Step 3: Assemble the First Layer. Take a large trifle bowl (about 3-4 quarts). Dip half of the ladyfingers quickly into the raspberry liqueur (or orange juice), just enough to moisten them without making them soggy. Arrange these moistened ladyfingers in a single layer at the bottom of the trifle bowl, breaking them if necessary to fit.
Step 4: Add Raspberry and Cream Layers. Spread half of the mascarpone cream evenly over the ladyfingers. Scatter half of the remaining fresh raspberries (about 1.25 cups) over the cream layer. Drizzle half of the cooled raspberry sauce over the raspberries.
Step 5: Repeat Layers. Repeat the dipping and layering process with the remaining ladyfingers, mascarpone cream, fresh raspberries, and raspberry sauce.
Step 6: Chill and Garnish. Cover the trifle with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the ladyfingers to soften further. Before serving, garnish with fresh mint leaves and a few extra fresh raspberries.
Step 7: Serve. Spoon the gorgeous raspberry dream trifle recipe into individual serving dishes and enjoy!