Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish. Prepare the Butter Pecan cake mix as per the package instructions, then pour the batter into the dish. Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean. Allow the cake to cool for about 10 minutes, then poke holes evenly across the surface using the handle of a wooden spoon.

In a medium saucepan over medium heat, combine 1 cup of brown sugar, 1/2 cup of butter, and 1/2 cup of heavy cream. Stir the mixture continuously until it bubbles and thickens, about 5-7 minutes. Remove from heat and allow to cool for a few minutes.

Pour the warm praline sauce evenly over the still-warm cake, ensuring it seeps into all the holes. Cover loosely and refrigerate for at least 2 hours.

In a chilled mixing bowl, add 1 cup of heavy whipping cream and beat with an electric mixer on medium speed. Gradually add 1/4 cup of powdered sugar and 1 teaspoon of vanilla extract. Continue whipping until you achieve stiff peaks.

Spread the whipped cream topping over the praline-soaked surface. Sprinkle chopped pecans on top. Slice into squares before serving.