Preheat oven to 350 degrees. Generously grease 2 (9-inch) round baking pans.
In a heavy saucepan, combine brown sugar, butter and cream. Cook and stir over low heat until sugar is dissolved. Pour into prepared baking pans. Sprinkle with pecans; cool.
For cake, in a large bowl, using a mixer, beat eggs, sugar and oil. Add pumpkin and vanilla. Combine flour, baking powder, pie spice, baking soda and salt; gradually add to pumpkin mixture just until blended.
Carefully spoon batter over brown sugar mixture. Bake in preheated oven for 30 to 35 minutes or until a toothpick inserted near the center comes out clean. Cool 5 minutes; remove from pans to wire racks to cool completely.
For topping, in a small bowl, beat cream until it begins to thicken. Add confectioners' sugar and vanilla; beat until stiff peaks form.
Place one cake layer praline side up on a serving plate. Spread with two-thirds of the whipped cream mixture over cake. Top with second cake layer and remaining whipped cream. Sprinkle with additional pecans if desired. Store in the refrigerator. Makes 14 servings. Enjoy!