Preheat oven to 350°F. Grease and flour three 8-inch round cake pans.
Prepare the cake mix according to the package directions using oil, water, and eggs.
Divide batter evenly among prepared pans. Bake for 22-26 minutes or until a toothpick inserted comes out clean. Let cakes cool completely.
Use the handle of a wooden spoon to poke holes all over the top of each cake layer.
Mix sweetened condensed milk and caramel topping together, then pour over each cake layer. Let sit until absorbed.
In a saucepan, melt butter over medium heat. Add brown sugar and milk. Bring to a boil and boil for 2 minutes, stirring constantly.
Remove from heat. Stir in powdered sugar and vanilla until smooth.
Place one cake layer on a plate or stand, top with praline frosting, and sprinkle with pecans. Repeat with remaining layers.
Garnish with extra pecans if desired. Chill until ready to serve.