Preheat your oven to 375°F and then grease and flour a 9½ cake pan.
In a medium sized bowl mix together the flour, spelt flour, salt, and baking powder.
In a separate bowl, beat the sugar, honey, and eggs on medium-high speed with a hand mixer for about two minutes.
Now, whisk in the Greek yogurt on low speed.
Finally, add the olive oil by slowly drizzling it in while mixing on low.
When combined, fold in the flour mixture by hand using a rubber spatula. Stop mixing as soon as everything is combined-- you don't want to over mix.
Fold in the diced apple just until incorporated.
Pour the batter into the greased and floured cake pan.