Preheat your oven to 350°F. Lightly grease or spray a 9" x 13" baking dish or pan and set aside.

For the topping, whisk together the sugar, salt, flour, and cinnamon. Slowly pour in the melted butter, stirring constantly until combined. Set aside.

For the filling, using a small bowl, simply mix together the brown sugar and cinnamon and set aside. The filling may seem like a lot but you will use all of it.

For the cake: using your stand mixer, beat together the butter, salt, both sugars, baking powder, and vanilla until well combined and smooth. Add in the eggs, one at a time, beating well after each addition. Use a rubber spatula to wipe down the bowl if needed.

Using a separate bowl, whisk together the yogurt and LACTAID milk until combined. If it’s a little lumpy, that’s fine. Add the flour into the butter mixture in your stand mixer, alternating with the yogurt and LACTAID mixture, starting and ending with the flour mixture; in 3 to 4 increments, mixing the batter to combine after each addition. Using a rubber spatula, gently fold in the chopped apples.

When ready to bake, pour about half of the batter into your prepared baking dish, using a rubber spatula to spread evenly, all the way to the edges of the pan. Sprinkle the filling evenly over the batter. Pour over the remaining batter over the filling. If desired, use a table knife to gently swirl the filling into the batter, as though you are making a marble cake. Lastly, sprinkle the topping all over the top.

Bake the cake for about 60 to 75 minutes, or until dark golden brown around the edges and a cake tester inserted into the center of the cake comes out clean. Remove the cake from the oven and allow it to cool for at least 20 minutes before cutting and serving. Enjoy with your mocha coffee!