In a small heavy saucepan, combine butter, whipping cream and brown sugar. Cook over low heat until butter is melted.
Pour into a 9x13-inch baking pan; sprinkle evenly with pecans.
In a large bowl, combine chocolate cake mix, water, vegetable oil and eggs until moist.
Carefully spoon half the batter around the edges and remainder inside.
Bake at 325 degrees for 50-60 minutes or until cake springs back when touched.
Cool 5 minutes, then invert onto a serving platter. Cool completely.