Preheat oven to 325° F and line an 8×8-inch baking pan with parchment paper, across the bottom and both sides. Toast the walnuts at 325° F for 10 minutes. Remove from oven and set aside.
In a food processor, blend together flour, baking soda, baking powder, sugar, cinnamon, salt and half of each dried fruit.
Transfer the mixture to a large bowl and mix in the walnuts and the rest of the dried fruit with your hands.
Whisk the vanilla and egg together, then add it to the fruit mixture.
Blend well and spread into the pan, packing it down with your fingers to even it out. Bake at 325° F until golden brown, about 35-40 minutes.
Remove from the oven and transfer to a wire rack by lifting the bars from the pan by the edges of the parchment paper. When cooled, use a sharp knife to cut into 12 pieces. Store in an airtight container at room temperature for up to 10 days.