Preheat your oven to 350°F (175°C).
In a large mixing bowl, cream the softened butter and granulated sugar until light and fluffy.
Add the eggs one at a time, mixing until well combined after each addition.
Stir in the vanilla extract and buttermilk.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, stirring just until combined.
Gently fold in the toasted pecans.
Pour the batter into the prepared pan and spread it evenly.
Bake in the preheated oven for 30–35 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 10 minutes before transferring it to a wire rack.
Once completely cooled, decorate with additional toasted pecans or frosting, if desired.