Chocolate Praline Upside-Down Cake

1 cup firmly packed brown sugar
1/2 cup butter
1/4 cup whipping cream
3/4 cup finely chopped pecans
2 1/4 cups cake flour
2 cups granulated sugar
3/4 cup sour cream
1/4 cup shortening
1 cup water
1 1/4 teaspoons baking soda
1 teaspoon salt
1 teaspoon vanilla extract
1/2 teaspoon baking powder
2 eggs
4 ounces unsweetened baking chocolate, melted and cooled
Whipped Cream Topping (recipe follows)
Pecan halves

Preheat oven to 350 degrees F. Grease and flour 3 (9 x 1 1/2-inch) round pans.

In a medium saucepan, heat brown sugar, butter and whipping cream over medium heat, stirring occasionally, until butter is melted. Divide among pans; spread evenly. Sprinkle with chopped pecans.

For cake batter, beat cake flour, sugar, sour cream, shortening, water, baking soda, salt, vanilla extract, baking powder, eggs and melted baking chocolate in large bowl of an electric mixer on low speed 30 seconds. Beat on high speed for 3 minutes. Pour batter over pecans in pans; spread evenly. Bake for 22 to 25 minutes, staggering cake pans in oven on middle racks for even heat flow. Cake layers are done when top springs back when touched lightly. Cool 5 minutes. Turn upside down onto wire racks; let pans sit for a few minutes before removing pans. Cool completely.

Place 1 layer, pecan side up, on cake plate. Spread with a third of the Whipped Cream Topping. Repeat with remaining layers. Garnish top of cake with a circle of pecan halves. Store covered in the refrigerator.

Whipped Cream Topping
1 cup whipping cream
2 tablespoons confectioners' sugar
1/2 teaspoon vanilla extract

Beat whipping cream, confectioners' sugar and vanilla extract in a chilled medium bowl with electric mixer on high speed until cream is stiff.