Preheat an oven to 325°F. Butter a 9 inch springform pan. Line the bottom with parchment paper and butter the paper. Zest the lemon. This will make about 2 teaspoons (2 grams) of zest. Cut the lemon in half and squeeze the juice through a strainer. You will need a 1/2 cup (135 grams) lemon juice. Pour the lemon juice over the Amaz!ns™ and soak for 5 to 10 minutes or until the Amaz!ns™ have soaked up most of the juice.
Mix together the butter, sugar, pecans, flour and salt until a crumbly meal forms. In food processor, process prunes and water until puréed.
In food processor, process prunes and water until puréed.
In a bowl, whisk together the prune purée, eggs, buttermilk and vanilla until nearly smooth (bits of prune purée will remain visible). In a stand mixer fitted with the paddle attachment, mix together the flour, sugar, baking powder, salt and lemon zest for 30 seconds. Add the butter and 1/2 cup (135 grams) of the prune purée mixture and mix on low speed until the ingredients are moistened. Increase the speed to medium and beat for 1 1/2 minutes or until the batter is light and fluffy. Stir in the remaining prune purée mixture on low speed until incorporated. Fold in the Amaz!ns™. Pour the batter into the prepared pan. Sprinkle the streusel on top of the batter, patting it lightly so it adheres to the surface. Bake for 60 to 70 minutes or until the center is set. Cool completely before unmolding.