Preheat the oven to 350 °F (180 ℃) and lightly spray a loaf pan with cooking spray then line with parchment paper.
To make the cinnamon swirl California Prune layer: In a small bowl, cover the minced California Prunes with boiling water for 15 minutes. In a separate small bowl, combine the sugar and cinnamon and mix well. Once the California Prunes have soaked for 15 minutes, drain them thoroughly and add them to the cinnamon-sugar mixture. Stir until completely combined, and then set aside.
To make the crumb topping: Meanwhile, in another small bowl make the crumb topping. Whisk the brown sugar and granulated sugar together. Then add the cinnamon, ginger, and salt. Pour in the melted butter then mix until combined. Use a fork to stir in the flour in 3 separate additions, until the flour is completely incorporated. Place in the refrigerator.
To make the cake layer: In another small bowl, whisk together the flour, baking powder, and salt. Set aside.
In a blender combine the egg, cottage cheese, buttermilk, and vanilla bean paste. Blend until smooth.
Cream together the granulated sugar and softened butter with an electric mixer until pale and fluffy, scraping down the sides as necessary. Add the flour mixture and the blended mixture in three additions, mixing until combined after each addition before adding the next, beginning and ending with the flour mixture.
Pour the cake layer batter into the prepared loaf pan spreading to the edges and smoothing the top with a spatula. Then spoon the prune mixture over the top evenly. Finally, crumble the crumb topping layer over the top.
Bake for 30-35 minutes until a toothpick inserted in the center comes out mostly clean with only a few crumbs. Cool for 15 -20 minutes before removing from the pan to a cooling rack. Slice and serve or store covered at room temperature for up to 3 days.