FOR THE APPLES:
Melt butter in a large pan over medium-high heat. When foaming and hot, add the remaining ingredients and sauté until caramelized lightly.
Spill contents of pan out on to a large plate and cool.

FOR STREUSEL:
Combine well with fingertips and set aside

FOR THE CAKE:
Butter and flour a 9 inch brownie pan, preheat oven to 350.
Whisk together the flour, salt, baking powder, baking soda and allspice. Reserve.
Cream together butter and sugar, adding the egg when combined well.
Add the flour mixture and the buttermilk in thirds top the sugar mixture, alternating as oyu go.
Batter will be stiff.
Fold in apples, place batter in brownie pan, cover evenly with streusel topping and bake for 45 minutes until a toothpick withdraws cleanly from the cake.
Cool and serve.