Step 1: In a medium saucepan, combine 3 cups of fresh or frozen raspberries, 1/2 cup granulated sugar, and 2 tablespoons of lemon juice. Bring to a gentle simmer over medium heat, stirring occasionally, and cook for about 5-7 minutes until raspberries soften and sugar dissolves. Remove from heat and let cool completely.
Step 2: In a large mixing bowl, using an electric mixer, beat the two 8-ounce packages of softened cream cheese with 1 cup of powdered sugar and 1 teaspoon of vanilla extract until the mixture is completely smooth, light, and fluffy, ensuring there are absolutely no lumps. In a separate, chilled large bowl, whip the 2 cups of cold heavy whipping cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until just combined.
Step 3: Begin by arranging about one-third of your pound cake cubes or ladyfingers at the bottom of a large trifle bowl (typically a 3-4 quart capacity works best), making sure to cover the bottom evenly.
Step 4: Spoon about one-third of the now completely cooled raspberry sauce over the cake layer, allowing it to soak in slightly.
Step 5: Carefully spread one-third of the fluffy cream cheese whipped cream mixture over the raspberry layer, using an offset spatula or the back of a spoon to gently create an even, smooth layer.
Step 6: Repeat the layering process twice more: add another layer of cake, then another layer of raspberry sauce, followed by another layer of the cream cheese mixture. Finish with a final generous layer of the cream cheese topping.
Step 7: Cover the trifle tightly with plastic wrap and refrigerate for at least 4 hours, or preferably overnight. This chilling period is crucial for flavors to meld and layers to set. Before serving, garnish with fresh raspberries and a few vibrant mint leaves, if desired.