Preheat oven to 350F.

Grease a medium loaf pan.

Beat the butter or margarine in a large mixing bowl. Add the brown sugar and beat until creamy.

Add the eggs, one at a time, beating after each addition. Beat in vanilla extract. Set aside.

In a medium bowl, mix the flour, baking powder, baking soda, salt, and spices.

Add about a third of the dry mixture to the butter mixture and stir well. Add half the pumpkin and stir.

Add another third of the dry mixture, and the rest of the pumpkin. Stir until incorporated.

Add the remaining third of the dry mixture and the yogurt. Mix well until combined.

Stir in the chocolate chips, cinnamon chocolate chips, and walnuts.

Scrape the batter into the prepared pan and spread evenly. Bake for 60 to 70 minutes or until a wooden skewer inserted into the centre comes out clean.

Let loaf cool for about 10 minutes before turning out onto a wire rack to cool completely before slicing.