Ingredients

• 3/4 cup Unbleached White All-Purpose Flour
• 3/4 cup Old Fashioned Rolled Oats
• 3/4 cup firmly packed Light Brown Sugar
• 1 Tbsp Ground Cinnamon
• 1/4 tsp freshly grated Nutmeg
• 1/4 tsp Kosher Salt
• 1/2 cup Unsalted Butter melted

• 2/3 cup firmly packed Light Brown Sugar
• 1 Tbsp Ground Cinnamon
• 1 tsp Cocoa Powder

• 2 1/2 cups Unbleached White All-Purpose Flour
• 2 tsp Ground Cinnamon
• 2 tsp Baking Powder
• 1/2 tsp Baking Soda
• 1/2 tsp Kosher Salt
• 1/2 tsp freshly grated Nutmeg
• 1/2 tsp Ground Ginger
• 1/2 cup Unsalted Butter room temperature
• 1/2 cup Granulated Sugar
• 1/2 cup firmly packed Light Brown Sugar
• 1 cup Sour Cream room temperature
• 1/4 cup Olive Oil
• 1 tsp Almond Extract
• 3 Eggs room temperature
• 2 Black Plums cut into 1/2-inch cubes, about 1 cup

Instructions

1. Preheat the oven to 350°F. Grease a 9-inch springform pan with butter or cooking spray and line the base with parchment paper. Dust with flour, tapping out the excess. Set aside.
2. Make the streusel: in a medium-sized bowl combine the flour, oats, brown sugar, cinnamon, nutmeg and salt. Using a spatula, add in melted butter and mix until everything comes together. Set aside.
3. Make the cinnamon swirl: combine all ingredients in a small bowl. Set aside.
4. Mix the all purpose flour, cinnamon, baking powder, baking soda, salt, grated nutmeg and grated ginger together in a separate bowl and whisk to combine. Set aside.
5. In the bowl of a stand mixer fitted with the paddle attachment, add the butter, granulated sugar and brown sugar. Turn the mixer to medium-high speed and mix until light and fluffy, about 3 minutes.
6. Turn the mixer to low and add the sour cream, olive oil and almond extract and mix to combine. Stop the mixer to scrape down the bowl, then add the eggs one at a time, beating well after each addition. Finally, slowly add the dry ingredients into the mixer and mix just until incorporated. Remove the bowl from the mixer and fold in the diced plums.
7. Pour half of the batter into the prepared pan and sprinkle with the cinnamon swirl mixture. Spread the remaining batter on top of the filling and, using a table knife, gently swirl the batter. Level the top of the cake and sprinkle the streusel over the top, crumbling it to the size of peas.
8. Bake the cake for 65-75 minutes, or until the streusel is a rich golden color and a knife inserted in the center comes out almost clean. Remove the cake from the oven and allow it to cool 20-25 minutes before cutting and serving.