Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with cupcake liners.

In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt. Set this dry mixture aside.

In a separate large bowl, mix the sugar (granulated and brown) with vegetable oil. Stir until smooth.

Add the eggs, one at a time, beating well after each addition. Then, stir in the milk and vanilla extract.

Gradually add the dry ingredients to the wet mixture, mixing just until combined. Don’t overmix—this keeps the cupcakes light and fluffy.

In a small bowl, combine the graham cracker crumbs, melted butter, and brown sugar. Stir until everything is well-coated and the crumbs form a loose, crumbly mixture.

Spoon about 1 tablespoon of the graham cracker mixture into the bottom of each cupcake liner, pressing down lightly to form a base.

Evenly divide the cupcake batter over the graham cracker crusts, filling each liner about ¾ full.

Bake for 18-20 minutes or until a toothpick inserted into the center of the cupcake comes out clean.

Let the cupcakes cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely.

Once the cupcakes are completely cool, top each one with mini marshmallows.

Using a kitchen torch, gently toast the marshmallows until golden brown. If you don’t have a torch, you can broil them in the oven for 1-2 minutes, keeping a close eye to avoid burning.

If desired, top with chocolate squares or chocolate chips for extra richness.