Preheat oven to 325°F (160°C). Grease and flour a bundt pan.
Cream butter, cream cheese, and sugar until fluffy (3–4 min).
Add eggs one at a time. Mix well. Stir in vanilla.
In another bowl, whisk flour, baking powder, salt, and cinnamon.
Add dry ingredients in thirds, alternating with buttermilk.
Mix swirl: brown sugar, cinnamon, melted butter, and pecans.
Layer half of batter in pan, sprinkle swirl mix, then top with remaining batter. Swirl lightly.
Bake for 70–80 minutes. Cool 15 minutes in pan. Turn onto rack.
Make glaze: Melt butter and brown sugar. Add cream, vanilla, and pecans.
Pour glaze over cooled cake. Let it set before slicing.
