Preheat the oven to 350°F (175°C) and grease a 9x13 inch cake pan.
In a mixing bowl, combine flour, granulated sugar, brown sugar, baking powder, baking soda, and salt. Stir until well mixed.
Add softened butter, buttermilk, eggs, and vanilla extract to the dry ingredients. Beat with a hand mixer on medium speed until smooth.
Fold in toasted pecans and pour the batter into the prepared cake pan.
Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
While the cake is baking, prepare the praline frosting by combining confectioners' sugar, heavy cream, and butter in a saucepan over medium heat. Stir until smooth and slightly thickened.
Once the cake is done, remove from the oven and let cool for 10 minutes. Pour praline frosting over warm cake and spread evenly.
Allow the cake to cool completely before slicing and serving.
Notes
For an extra special touch, garnish the cake with whole pecans or a dusting of confectioners' sugar before serving.