Preheat oven to 325 degrees
Spray or use butter to coat pan and set aside
In a medium bowl combine 2 3/4 cups of flour, baking powder and salt, mix together and set aside.
In a large bowl blend the butter, cream cheese and sugar together by hand or with an electric mixer.
Add in eggs and vanilla.
add 1/4 flour over blueberries and fold into batter
Pour batter into pan
Bake in oven for 60 -70 minutes or until toothpick comes clean