Preheat your oven to 350°F (175°C).
Grease your loaf pan with butter generously.
Line it with parchment paper for easy removal.
This prevents the cake from sticking to sides.
Combine flour, baking powder, and salt together.
Whisk them well in a medium bowl.
Set this mixture aside for later use.
Beat softened butter and sugar until light and fluffy.
This should take about 3-4 minutes with mixer.
The mixture should look pale and creamy now.
Add eggs one at a time to mixture.
Beat well after adding each single egg.
This creates a smooth and consistent batter.
Mix in sour cream and vanilla extract gently.
Blend until everything is well combined and smooth.
Fold the dry ingredients into wet mixture slowly.
Don't overmix or cake will become tough.
Mix just until you see no flour streaks.
Toss cranberries with 2 tablespoons of flour.
This prevents them from sinking to the bottom.
Gently fold cranberries into the batter carefully.
Pour batter into your prepared loaf pan evenly.
Bake for 60-70 minutes until golden brown.
A toothpick should come out clean when inserted.
Let cake cool in pan for 15 minutes.
Transfer to a cooling rack to cool completely.
Slice and enjoy with your loved ones.