Preparation Steps

• Line an 8-inch square pan with parchment, leaving overhang on two sides for easy lifting. Test-fit a layer of graham crackers so you know how they’ll arrange later; set aside.
• Make the compote: Set aside 1/2 cup blueberries. In a medium skillet over medium heat, combine remaining blueberries, granulated sugar, lemon juice, and a pinch of salt. Cook, stirring, until the berries release juices and some begin to burst, 4–5 minutes. Stir together cornstarch and water, then drizzle into the pan. Simmer 1–2 minutes more, stirring, until glossy and lightly thickened. Off heat, fold in the reserved blueberries.
• Quick-cool the compote by spreading it on a plate or small sheet pan; refrigerate while you prepare the cream so it’s cool to the touch before layering.
• Whip the cream: Chill a mixing bowl and beaters for 5 minutes. Beat heavy cream on medium-high to soft peaks, 2–3 minutes. Add powdered sugar and vanilla; continue beating to medium-firm peaks. Reserve about 3/4 cup whipped cream for the top; keep chilled.
• Make the lemon cheesecake cream: In a separate bowl, beat the softened cream cheese, granulated sugar, lemon zest, and salt until smooth and fluffy, 1–2 minutes. Fold in the remaining whipped cream in two additions until silky and no streaks remain.
• Assemble layer 1: Swipe a spoonful of lemon cream across the pan (this anchors the crackers). Arrange a snug single layer of graham crackers. Spread half of the lemon cream evenly to the edges. Spoon half of the cooled blueberry compote over top and gently ripple it through the cream with a butter knife, leaving a small border so it doesn’t spill over.
• Assemble layer 2: Add another full layer of graham crackers. Spread the remaining lemon cream, then the rest of the compote, marbling it lightly. Do not add a final cracker layer—this keeps the top soft and mousse-like.
• Finish and chill: Spoon the reserved whipped cream over the top and swoop decoratively. Cover and refrigerate at least 4 hours, preferably overnight, so the crackers soften into cake-like layers.
• Serve: Lift the cake out by the parchment. Garnish with extra blueberries and lemon zest if using. For clean slices, chill in the freezer for 15–20 minutes before cutting and wipe the knife between cuts.