Preheat oven to 350°F (175°C). Grease and flour a 9-inch springform pan.

In a large bowl, combine flour and 3/4 cup sugar.

Cut in cold, diced butter using a pastry blender or fork until the mixture resembles coarse crumbs.

Set aside 1 cup of crumb mixture for the topping.

In the remaining crumb mixture, stir in baking powder, baking soda, and salt.

Blend in sour cream, 1 egg, and vanilla extract until just combined.

Spread the batter into the bottom and slightly up the sides of the prepared pan.

In a small bowl, blend cream cheese, 1/4 cup sugar, and 1 egg until smooth.

Spread the cream cheese mixture evenly over the batter in the pan.

Drop spoonfuls of raspberry preserves over the cream cheese layer.

In a separate small bowl, combine the reserved crumb mixture and chopped pecans.

Sprinkle the pecan streusel evenly over the raspberry preserves.

Bake for 50-60 minutes, or until the cream cheese mixture is set and the crust is a deep golden brown.

Let the cake cool in the pan for 15 minutes before removing the sides of the pan.

Serve warm or chilled.