Heat the oven to 325°F. Thoroughly grease and flour a 10-inch Bundt or tube pan, or coat it with baking spray that contains flour.

If preparing the pecan-butter mixture, melt 2 tablespoons of butter in a skillet. Add the chopped pecans and brown sugar, cook for 3 to 5 minutes while stirring until fragrant, and cool completely.

Whisk the flour, baking powder, and salt together in a medium bowl.

Beat the softened butter and granulated sugar with a mixer for 4 to 6 minutes, until very light and fluffy.

Add the eggs one at a time, beating well after each addition and scraping down the bowl as needed.

Add the flour mixture in three additions, alternating with the buttermilk in two additions. Mix only until the batter is combined.

Fold in the vanilla and pecans by hand, including the cooled pecan-butter mixture if using. Avoid overmixing.

Pour the batter into the prepared pan and smooth the surface. Bake for 75 to 90 minutes, beginning to check at 75 minutes, until a long skewer inserted into the thickest part comes out with only a few moist crumbs.

Cool the cake in the pan for 10 to 15 minutes, then invert it onto a cooling rack. Let it cool for at least 45 minutes and preferably until completely cool before slicing or glazing.

For the glaze, melt the butter, brown sugar, cream, and salt in a saucepan. Simmer for 2 to 3 minutes, remove from the heat, stir in the vanilla, and spoon over the cooled cake.