Preheat oven to 350 degrees F. Liberally grease a 9" round springform pan with cooking spray and set aside.
In a medium bowl, prepare your streusel: combine the brown sugar, flour, lemon zest, melted butter, slivered almonds, and pinch salt together until clumps of streusel form. Set aside.
To make the cake: Cream together the butter and sugar together until light and fluffy, about 2 minutes. Beat in the eggs, one at a time, followed by the vanilla, almond extract and lemon juice. Beat in the sour cream, flour, baking powder & soda, salt and the lemon zest until a thick batter forms. Spread the batter into the prepared pan. Top with all of the streusel. It will seem like a LOT of streusel, but use all of it!
Bake for approx. 50-60 minutes or until a toothpick inserted near the center comes out clean or with moist, not wet, crumbs. Cool completely.
Just before serving, make the glaze. In a small bowl combine the powdered sugar, lemon juice and vanilla until smooth. Drizzle over the top of the cake before cutting into wedges.