Pre-heat your oven to 375 degrees, and line a muffin tray with paper liners.
In a large bowl, mix your dry ingredients together -- the flours, sugar, leaveners, salt, cinnamon, and zest. Then, stir in the dates and chopped nuts.
In a smaller bowl, stir together your wet ingredients -- juice, egg, buttermilk, vanilla, and butter -- until smooth.
Add the wet ingredients to the dry, and mix until a batter has formed; do not overmix. Spoon the batter into your muffin liners, and bake for 15-18 minutes at 375 degrees.