Preheat Oven & Prepare Pan Preheat oven to 300°F/150°C. Grease a tube pan with cooking spray. Set aside.
In a stand mixer, beat butter and sugar until fluffy, about 5-7 mins. Add sour cream.
Beat in eggs gradually, ensuring thorough mixing after each addition.
Combine flour, baking powder, baking soda, and salt. Add to the batter, followed by milk and vanilla. Stir gently, avoid overmixing.
Pour batter into greased pan. Tap to remove air bubbles. Bake at 300°F for 60-70 minutes until a tester comes out clean.