Place raspberries, 1 tablespoon sugar, and 1 teaspoon vanilla in a small saucepan. Simmer over medium heat for 5–8 minutes until the fruit breaks down and the sauce thickens.

Strain the mixture through a fine mesh sieve to remove seeds, pressing with the back of a spoon; set the seedless sauce aside to cool.

Beat the room-temperature cream cheese with 1/3 cup sugar until smooth. Add 1 large egg and 1/2 teaspoon vanilla, then mix until creamy.

Whisk together 1 cup flour, 3/4 cup cocoa powder, and 1/4 teaspoon salt in a medium bowl.

In a separate large bowl, whisk 3/4 cup + 2 tablespoons neutral oil with 1 1/2 cups sugar and 1 tablespoon vanilla.

Add the 3 large eggs one at a time, whisking well after each addition until glossy.

Gently fold the dry ingredients into the wet until no streaks remain.

Line a baking pan with parchment and spread the brownie batter into an even layer.

Spoon the cheesecake mixture over the brownie batter, then drop spoonfuls of cooled raspberry sauce over the cheesecake layer and swirl to create marbled hearts.

Bake at 350°F (175°C) for 30–35 minutes until edges are set.

Cool completely on a wire rack, then refrigerate for at least 2 hours.

Use a small heart-shaped cookie cutter to stamp neat hearts from the chilled slab.