Heat oven to 350°F (325°F for dark or nonstick pan). Spray bottom only of 13 x 9-inch pan with cooking spray.
Step
2
In medium microwavable bowl, microwave 2 tablespoons butter, 2 tablespoons brown sugar and 1/2 cup chopped pecans uncovered on High 1 minute; stir. Continue to microwave in 15-second increments until mixture is bubbling and hot; stir. Set aside.
Step
3
In large bowl, beat cake mix, sour cream, water, vegetable oil and eggs with electric mixer on medium speed 2 minutes. Stir in pecan mixture. Pour into pan.
Step
4
Bake 26 to 31 minutes or until toothpick inserted in center comes out clean. Cool completely in pan on cooling rack, about 1 hour.
Step
5
In 2-quart heavy saucepan, add 1/2 cup butter, 2 cups brown sugar and whipping cream. Bring to a boil over medium-high heat, stirring frequently. Boil and stir 1 minute; remove from heat. Whisk in powdered sugar and vanilla until smooth. Stir in 2 cups pecans. Cool 10 minutes, stirring occasionally, until frosting begins to thicken. Spread warm frosting over cake. Cool 30 minutes before serving. Store tightly covered at room temperature.
Light or dark brown sugar works for this recipe. Dark brown sugar will yield a more molasses-forward flavor, whereas light brown sugar will yield a more mild sweetness.
You can use pre-chopped pecans, which are often found in the baking aisle at the grocery store. Or, you can use pecan halves and chop them yourself. Be sure to measure them after chopping for this recipe.
Sprinkle frosted cake with toffee bits for even more flavor and crunch.
