For the cake...
1/2 cup margarine
1/4 cup whipping cream
1 cup brown sugar
3/4 cup chopped pecans
1 package Devil's Food Cake mix
1 1/4 cup water
1/3 vegetable oil
3 eggs

For the frosting...
1 3/4 cup whipping cream
1/4 cup confectioner's sugar
1/4 teaspoon vanilla
Optional: whole pecans or chocolate curls

1. Make the cake.
   1. In a small, heavy saucepan, combine butter, 1/4 cup whipping cream, and brown sugar. Cook over low heat - stirring occasionally - just until butter is melted.
   2. Pour melted mixture into two 9" pans, and sprinkle evenly with chipped pecans.
   3. Prepare cake mix according to instructions.
   4. Carefully spoon the cake batter over the pecan layer.
   5. Bake at 325 degrees for 35 - 45 minutes. Cool 5 minutes.
2. Make the frosting.
   1. In a small bowl, beat 1 3/4 cup whipping cream until soft peaks form.
   2. Blend 1/4 confectioner's sugar and vanilla.
   3. Beat until stiff peaks form.
3. Assemble.
   1. Flip one of the baked cakes onto a serving plate so the praline is facing up.
   2. Top with half of the whipped cream frosting.
   3. Layer the second cake - praline-side-up - on top of the frosted cake.
   4. Top the second cake with the remaining whipped cream frosting.
   5. Garnish with pecans and chocolate curls if desired.
4. Refrigerate.