Spray a 10 inch spring-form pan with vegetable cooking spray and place on a baking sheet.
In a medium bowl combine the cracker crumbs, almond flour (or ground almonds), Splenda and melted butter. Press into the bottom of the prepared pan. Bake for 10 minutes. Allow to cool while making the filling.
In a large bowl whip the softened cream cheese until smooth. The longer you beat, the fluffier and higher the cake will become, but may be more prone to cracks. This does not affect the flavor. Beat in the Splenda, vanilla and almond extracts. Beat in the eggs one at a time just until blended. Beat in the half & half and flour just until combined. Pour into cooled crust and bake for 45 minutes to 1 hour or until set on the edges and jiggly in the very center with about a 3-inch firm ring around the pan's edges. Keep oven on.
In a small bowl whisk together the sour cream, 1/4 cup Splenda, and vanilla extract. Beginning at the edges of the baked cheesecake, spread the topping evenly. Return to the oven for 5 minutes.
Allow to cool on a wire rack for 10 minutes. Run a sharp knife around the edge and cool completely before removing the sides of the pan. Wrap tightly and chill overnight.