Line a 9x9-inch baking pan with wax paper or parchment paper.

Melt the butter in a medium saucepan over medium heat.

Add granulated sugar and unsweetened cocoa powder to the melted butter, stirring until combined.

Pour in the evaporated milk and bring the mixture to a boil, stirring constantly.

Boil for 5 minutes, stirring to maintain a smooth consistency.

Remove from heat and stir in Jet Puffed marshmallow crème and vanilla extract until smooth.

Stir in semi-sweet chocolate chips until melted and fully incorporated.

Pour the fudge mixture into the prepared pan, smooth the top, let cool at room temperature for 1 hour, then refrigerate for 2 hours until set.