Preheat the oven to 350ºF. Generously grease the bundt pan with butter.

Cream the softened butter and brown sugar together until light and fluffy, about 3-5 minutes.

Gradually add the beaten eggs into the butter and sugar mixture. Make sure that the eggs are completely incorporated after each addition.

In a small bowl, add the pumpkin pie mix, Greek yogurt, and vanilla. Mix together until fully combined and smooth.

In another bowl, sift the flour and baking soda together before mixing to fully incorporate.

Gently fold in one third of the pumpkin mixture, followed by one third of the flour mixture. Continue alternatively adding the rest of the mixtures until fully combined and a smooth batter comes together.

Remove one third of the pumpkin batter and place in a small bowl. Add the cocoa powder and whole milk. Mix together until fully combined and smooth.

Add the dark chocolate chips to the remaining pumpkin batter and gently fold in until the chocolate chips are evenly dispersed in the batter.

Alternatively add the chocolate and pumpkin batters into the greased bundt pan, swirling the batter to create a marbled design.

Bake for 50 minutes, until the cake reaches 210ºF or a toothpick inserted comes out clean,

Remove the cake from the oven and cool for 15 minutes before flipping onto a cooling rack. Allow the cake to cook completely before serving.

Enjoy!