Line the bottom of a 9" round springform pan with parchment paper.

Cut an additional circle of parchment slightly larger than the base. Set aside.

Bring a small pot of water to a boil, then reduce to a simmer. Place the chocolate pieces into a heat-safe bowl and place the bowl over the water (this creates a double boiler).

Cook, stirring occasionally, until the chocolate has melted completely.

Pour slightly less than half of the chocolate into the prepared pan, tilting and gently shaking it until it completely covers the bottom.

Return the bowl of chocolate to the pot of simmering water to keep it warm and place the pan of chocolate into the freezer to harden while you make the filling.

Combine the remaining ingredients in a large bowl and beat on high until a thick, mostly cohesive dough forms.

Place the filling on a piece of parchment paper and knead with your hands to form a ball.

Roll out to just slightly smaller than your pan, dusting with powdered sugar as needed to keep it from sticking to your rolling pin.

Remove the springform pan from the freezer and place the filling on top of the chocolate inside it. Use your fingers to work it nearly to the sides of the pan.

Cover with the remaining chocolate, spreading it into place with an offset spatula as needed.

Crumple up the piece of parchment you previously set aside, smooth it back out, and gently press it onto the top of the chocolate to create that signature patty ripple.

Return to the freezer for 10-15 minutes, or until set.