• Preheat oven to 350°F. Grease and flour a 12-15 cup Bundt pan, tapping out excess flour (or use a commercial cake release spray [like Wilton or Baker's Joy] or homemade cake goop). Adjust the oven rack down to the bottom third of the oven.

To make the pumpkin spice cake:

• In a medium bowl, whisk together white whole wheat flour, oat flour, baking powder, salt, cinnamon, ginger, cloves and nutmeg. Set aside.
  196 g white whole wheat flour, 60 g oat flour, 10 g baking powder, 6 g baking soda, 6 g salt, 6 g ground cinnamon, 3 g ground ginger, 1/4 tsp ground cloves, 1/4 tsp ground nutmeg
• In a large liquid measuring cup with a spout, whisk together buttermilk and vanilla until fully combined. Set aside.
  320 g buttermilk, 5 g vanilla
• In a large mixing bowl, beat the oil, butter and sugars with an electric mixer until fully combined and lightened in color, about 3-5 minutes. Add the eggs one at a time beating until the egg is fully incorporated after each addition.
  113 g vegetable oil, 112 g unsalted butter, 150 g sugar, 165 g brown sugar, 3 large eggs
• Beat the pumpkin into the egg and butter mixture until it is fully combined. It may look slightly curdled at this point, especially if any of your ingredients are not fully up to room temperature, don't worry, it will come together in the next step. Alternate adding the flour mixture and the buttermilk mixture - 1/3 flour mixture followed by 1/2 buttermilk - starting and ending with the flour mixture. Stir after each addition just until no unmixed pockets of ingredients remain. The final mixture should be a smooth, thick batter.
  425 g pumpkin puree
• Pour the batter into the prepared Bundt pan - tap on the counter to release any bubbles or air pockets.

To make the ricotta cheesecake:

• In a medium bowl, combine ricotta, yogurt, eggs, sugar, cornstarch, vanilla, and salt. Whisk until combined. Carefully pour all over the top of the cake batter in the Bundt pan. Jiggle the pan a bit to even out the cheese mixture, if necessary.
  284 g ricotta cheese, 142 g Greek yogurt, 2 large eggs, 100 g toasted sugar, 16 g corn starch, 15 g vanilla bean paste, 3 g salt
• Bake for 75-90 minutes or until toothpick inserted in center comes out clean (or internal temperature of ~205°F). Remove from the oven and allow to cool for 15 minutes in the pan.
• Place a cooling rack on top of the cake and flip cake over and out onto rack. Allow to cool completely before slicing and serving. Store leftovers in the refrigerator.