Preheat the oven to 350 degrees F (180 degrees C).
Grease and flour a 12x9-inch baking pan which is 2-inches deep.
In a large bowl stir in the Brown Sugar (4 cup), Cake Flour (1/2 cup), Oat Bran (1 1/2 cup), Old Fashioned Rolled Oats (1 cup), Ground Cinnamon (1 teaspoon), Dry Mixed Spice (1 teaspoon), Ground Nutmeg (1/2 teaspoon), Salt (1/2 teaspoon), Baking Powder (1/2 teaspoon), Dates (1 cup), Dried Mangoes (1 cup), Pumpkin Seeds (1/2 cup) and Sunflower Seeds (1/2 cup). Stir in the dried fruit and seeds.
In another bowl, lightly beat the Egg (2) then add Butter (3/4 cup), Coconut Oil (1/2 cup), Honey (5 tablespoon), Plain Greek Yogurt (1 cup) and mix well. Pour the wet ingredients into the dry ingredients and mix well. The mixture should be thick and sticky, be sure to incorporate all the flour!
Press the mixture firmly and evenly into the baking pan.
Place in the middle of the oven and bake for 1 hour or until the rusks are going golden brown.
Cool on a cooling rack for about 20 minutes.
Using a sharp serrated knife and cut the rusks into oblongs about 0.7 inch x 2.3 inch.
Place the rusks on two large baking trays and bake for about 6 hours at 160 degrees F (70 degrees C) until they have dried out all the way through. Cool completely on cooling racks and then store in airtight containers and keep in a cool dry place. Enjoy with tea!