Preheat the oven to 350°F/180°C. Grease a 9x9-in. baking pan.
Combine the topping ingredients in a small skillet. Using medium heat, stir the walnuts until they are thoroughly coated with the honey. Remove from the heat and reserve.
In a medium bowl, combine the oil, honey and vanilla. Add the egg and beat well. Add the yogurt, cider, orange zest, apple butter and raisins; mix to combine.
In another medium bowl, combine the dry ingredients and add them to the liquid ingredients.
Pour the batter into the baking pan and top with walnut mixture. Bake for 35 - 40 minutes. The cake is done when a wooden pick inserted into the middle of the cake comes out clean.
Before serving, drizzle with the 2 Tbsp. of honey over the top of cake (optional).