1. In a small saucepan, combine 1 1/2 cups raspberries, 1/4 cup sugar, and lemon juice. Cook over medium heat, stirring occasionally, for 5–7 minutes until raspberries break down. Strain to remove seeds and cool. 2. In a large bowl, whip heavy cream with remaining 1/4 cup sugar until soft peaks form. In another bowl, whisk mascarpone and vanilla until smooth. Fold whipped cream into mascarpone gently. 3. Briefly dip ladyfingers into raspberry liqueur or lemon juice and arrange a layer in a trifle dish or 9×9-inch pan. Spread half of mascarpone mixture over, drizzle with raspberry sauce. Repeat layers. 4. Cover and chill at least 4 hours or overnight. 5. Garnish with fresh raspberries, dust with powdered sugar, and add mint if desired before serving.