Preheat your oven to 350°F (175°C). In a large mixing bowl, combine the butter pecan cake mix, eggs, water, and chopped pecans. Use an electric mixer to beat the mixture on medium speed for about 2 minutes until smooth and well-blended. Pour the batter into a greased 9x13-inch baking pan and bake for 28-32 minutes, or until a toothpick inserted in the center comes out clean and the top is golden brown.

Once the cake has baked, allow it to cool in the pan for about 10-15 minutes. Using a fork, poke holes all over the surface of the warm cake, making sure to create ample openings for the praline sauce. In a small bowl, mix together the sweetened condensed milk and brown sugar, then pour this mixture evenly over the cake, ensuring it seeps into the holes for maximum flavor absorption.

In a medium saucepan over medium heat, melt the butter. Add in the remaining brown sugar and stir continuously until the mixture becomes a smooth, velvety sauce—about 3-5 minutes. Once it reaches a caramel-like consistency, remove it from the heat and allow it to cool for a few minutes before drizzling generously over the poked cake, letting it soak in for an indulgent treat.

Cover the cake with plastic wrap and refrigerate for at least 2 hours, or overnight if you prefer to prepare ahead. This chilling process allows the flavors of the Butter Pecan Praline Poke Cake to meld beautifully, enhancing the overall taste and making it even more scrumptious when served.

In a mixing bowl, use an electric mixer to whip the heavy cream and powdered sugar together on medium speed until soft peaks form, which usually takes about 3-5 minutes. Add the vanilla extract and whip for an additional 30 seconds to incorporate it fully. Carefully spread the whipped cream over the chilled cake, creating an even layer that enhances the cake's decadent appeal.

Just before serving, sprinkle extra pecan pieces on top of the whipped cream for added crunch and a beautiful presentation. You can optionally chill the assembled cake briefly for about 15 minutes to set the topping, making it easier to slice and serve. Enjoy the delightful flavors of your homemade Butter Pecan Praline Poke Cake!