Step 1: Make the Graham Cracker Crust

1. In a medium bowl, mix 250 g crushed graham crackers, 1 tablespoon brown sugar, and 100 g melted butter until it looks like wet sand and holds together when squeezed.

2. Pour the mixture into a 6-inch fluted, 2-inch deep tart pan. Press it firmly into the bottom and up the sides using your fingers or the back of a spoon.

3. Chill the crust in the fridge for at least 30 minutes while you prepare the filling.

4. Tip: Use a flat-bottomed glass to press the crumbs for an even, compact crust.

Step 2: Prepare the Chocolate Ganache

1. Place 300 g chopped chocolate in a heat-safe bowl and set aside.

2. In a small pot, heat 300 g heavy cream over medium heat until small bubbles form around the edges and it just begins to simmer (don’t boil).

3. Pour the hot cream over the chocolate and let it sit undisturbed for 5 minutes.

4. Slowly whisk the mixture in circles until the chocolate melts completely and the ganache is thick and smooth. It may look curdled at first—keep whisking!

5. Let the ganache cool slightly (about 5 minutes) to avoid melting the crust.

6. Tip: If the ganache is too thick, warm it gently over a double boiler to loosen it up.

Step 3: Assemble the Tart

1. Remove the chilled crust from the fridge.

2. Pour the ganache into the crust and smooth the top with an offset spatula or the back of a spoon.

3. Refrigerate the tart for at least 2 hours, or until the ganache is set and firm to the touch.

4. Tip: Tap the pan gently on the counter to remove air bubbles before chilling.

Step 4: Make the Marshmallow Meringue

1. Bring about an inch of water to a simmer in a small pot.

2. In a heat-safe bowl that fits over the pot without touching the water, combine 3 egg whites and 150 g granulated sugar.

3. Place the bowl over the simmering water and stir often until the sugar dissolves completely (4–5 minutes). Test by rubbing a bit of the mixture between your fingers—it should feel smooth, not grainy.

4. Remove the bowl from the heat and add ¼ teaspoon cream of tartar and 1 teaspoon vanilla extract.

5. Using a hand mixer or stand mixer, whisk on low speed, gradually increasing to high. Beat until stiff peaks form (5–7 minutes). The meringue should stand upright when the whisk is lifted.

6. Tip: Ensure your bowl and whisk are grease-free for the best meringue texture.

Step 5: Decorate and Toast

1. Remove the tart from the fridge and spoon the meringue on top, spreading it evenly with a spatula.

2. Create a spiky look by gently touching the spatula to the meringue and pulling away, repeating across the surface.

3. Using a kitchen blowtorch on a low setting, carefully toast the meringue until golden brown in spots.

4. If the ganache softens from the torch, chill the tart for 15–20 minutes to set again.

5. Tip: No blowtorch? Serve the meringue untoasted, or place the tart under a broiler for 30–60 seconds, watching closely to avoid burning.