Beat butter and cream cheese at medium speed with an electric mixer until creamy.
Gradually add sugar, beating until light and fluffy.
Add egg beating just until blended.
In a separate bowl, combine flour, salt, baking soda, baking powder and chai mix; gradually add to butter mixture, beating at low speed just until blended.
Stir in banana and vanilla. Spoon batter into a greased and floured 8- x 4-inch loaf pan.
Bake at 350° for 1 hour or until a long wooden pick inserted in center comes out clean and sides pull away from pan, shielding with aluminum foil last 15 minutes to prevent browning, if necessary. Cool bread in pan on wire racks 10 minutes. Remove from pan, and cool 30 minutes on wire racks before slicing.
For the Chai mix: I make this and keep it on hand to add to smoothies. Combine all ingredients (ground) and keep in an air tight container.