Preheat oven to 350 degrees F. Lightly coat bottom and sides of 9 x 5 x2-inch loaf pan with olive oil spray.
Streusel: in a small bowl, combine all ingredients with a fork.
Dry Ingredients: gently spoon flour into measuring cup; leveling with a butter knife. In a medium bowl, add flour and remaining dry ingredients, sifting mixture twice.
In bowl of electric mixer (can also use a hand mixer), beat butter on high speed until creamy, about 1 minute. Gradually add coconut palm sugar, continuing to beat until light and fluffy, about 1 minute. On medium speed, add eggs, 1 at a time, beating well after each addition. Beat in vanilla.
On low speed, beat in flour mixture, alternately with buttermilk, beginning and ending with flour mixture just until incorporated. Allow batter to sit for 30 minutes.
Pour 1/2 of the batter into prepared pan. Sprinkle streusel over batter, reserving 2 tablespoons for topping. Add remaining batter, spreading evenly. Sprinkle with reserved streusel.
Bake for 40 to 45 minutes or until a toothpick inserted into center comes out clean. (Bread may crack a bit in the center-okay.) Remove bread from oven. Cool on a rack for 15 minutes. With a sharp knife, carefully loosen bread around edges; remove from pan. Let bread finish cooling on rack.