Apple Streusel Cake

I found this recipe in a cookbook of mine and was originally called Apple Streusel Bars, but after I made it for the first time and changed a few things since, it has become what is known know by

Apple Streusel Cake
prep time: 30-60 minutes
bake time: 45-60 minutes

Batter:
1/2 cup of soften unsalted butter
3/4 cup of superfine sugar
1 tsp vanilla extract
2 eggs, beaten
1 cup all-purpose flour
2 Granny Smith apples, peeled, cored, and diced

Streusel Topping:
Normally I use this recipe
1/4 cup all-purpose flour
1/4 cup light brown sugar
1/2 tsp ground cinnimon
2 tbsp melted butter

But for the pictured above, I had leftover graham cracker crumbs, so I did this:
1 cup or 1 pan of crushed graham crackers
2 tbsp of superfine sugar
3-4 tbsp melted butter


Set the oven to 350 F. Cream the butter and sugar together. Add the vanilla extract. Gradually mix in the eggs. Sift the flour in and fold evenly. Finally, stir in the apples

Spread in a 9x9 in pan. For the topping, mix the graham cracker crumbs with the sugar. Add the melted butter and mix. Hopefully there was enough butter to make little clumps of topping (I ran out of butter so I only used 2 tbsp when I made my topping, so it was majority just crumbs than streusel-ish toppings). Sprinkle the batter with the toppings and bake for 44-45 minutes.