Grease either 2 8X4 loaf pans or a 9X13 pan with butter.
Combine the thin apple slices with the lemon juice and sugar,stirring to coat well and set aside.
Combine the topping ingredients in a small bowl and mix with a fork until crumbly.
In a bowl of a stand mixer combine half of the flour, sugar, yeast and salt and mix to combine.
Heat the butter and milk together until the butter is melted and the temperature is 120 deg f. Slowly add this to the flour mixture. Beat on medium until combined, about 2 minutes.
Add in the egg, vanilla and mix well again and then add the rest of the flour and mix on low until a stiff batter forms.
Spread a little less than half the mixture on the bottom of the prepared pans, it is pretty stiff and stretchy so work slowly to not over work the batter. Place the apple slices over the batter and cover with the remaining batter. Gently press the apple halves into the top of the batter, arranging in any pattern desired. Sprinkle the topping over the batter avoiding the tops of the sliced apples. Cover pan with a towel and let rest in a warm, draft free area until batter has doubled in size, at least an hour
Preheat oven to 350 deg F
Uncover the pan or pans and bake for 20-30 minutes or until done. Let cool in pans on a wire rack. If made in loaf pans carefully remove from pans and set on a plate to cool. Can be served room temperature or warmed with a scoop of vanilla ice cream.