Cook first 3 ingredients in a saucepan over low heat, stirring until sugar dissolves. Pour into 2 greased 9-inch round cakepans; sprinkle evenly with 3/4 cup pecans. Cool.
Beat eggs, sugar, and oil at medium speed with an electric mixer. Add pumpkin and vanilla; beat well.
Combine flour and next 4 ingredients; add to pumpkin mixture, beating until blended. Spoon batter evenly into prepared cakepans.
Bake at 350° for 30 to 35 minutes or until a wooden pick inserted in center comes out clean. Cool cake layers in pans on wire racks 5 minutes; remove from pans, and cool on wire racks.
Place 1 cake layer on a serving plate, praline side up; spread evenly with Whipped Cream Topping. Top with remaining layer, praline side up, and spread remaining Whipped Cream Topping over top of cake. Sprinkle cake with chopped pecans. Store in refrigerator.