Preparation Steps

• Prepare the raspberry swirl: In a small saucepan, combine 2 cups of raspberries, 0.25 cup of sugar, and 1 tablespoon of lemon juice. Cook over medium heat, stirring occasionally, until the raspberries break down and the mixture thickens, about 5-7 minutes. Strain through a fine-mesh sieve to remove seeds, then set aside to cool.
• Make the mascarpone cream: In a heatproof bowl set over a saucepan of simmering water (double boiler), whisk together the egg yolks and 0.5 cup of sugar until pale and thick, about 5-7 minutes. Remove from heat and let cool slightly. In a separate bowl, beat the softened mascarpone cheese with 1 teaspoon of vanilla extract until smooth. Gently fold the cooled egg yolk mixture into the mascarpone. Fold in the whipped heavy cream until just combined.
• Assemble the tiramisu: In a shallow dish, combine the cooled brewed coffee and coffee liqueur (if using). Quickly dip each ladyfinger into the coffee mixture, ensuring they are moistened but not soggy. Arrange a single layer of dipped ladyfingers in the bottom of an 8x8 inch baking dish. Spread half of the mascarpone cream evenly over the ladyfingers. Dollop spoonfuls of the cooled raspberry swirl over the cream and gently swirl it in with a toothpick or knife. Repeat with another layer of dipped ladyfingers and the remaining mascarpone cream and raspberry swirl.
• Chill: Cover the baking dish with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the tiramisu to set.
• Serve: Garnish with fresh raspberries before serving.