For the Apple Cake:
- 3 cups all-purpose flour, divided
- 2 teaspoon baking powder
- 1 teaspoon cinnamon
- ½ teaspoon salt
- 1 cup unsalted butter, softened
- 2 cups granulated sugar
- 2 teaspoons vanilla extract
- 4 large eggs
- 1 cup whole milk
- 3 cups apples (peeled and diced into ½ inch cubes or smaller)
- ½ cup chopped pecans
For the Pecan Crunch:
- ½ cup quick cooking oats
- ¼ cup chopped pecans
- ¼ cup brown sugar
- ¼ cup all-purpose flour
- 3 tablespoons unsalted butter, softened
- 2 tablespoons honey
- pinch salt
For the Cinnamon Buttercream:
- 6 large egg whites
- 2 cups granulated sugar
- 3 cups unsalted butter, softened
- 2 teaspoon vanilla extract
- ¾ teaspoon cinnamon, or to taste
For the Toffee Sauce:
- 6 tablespoons unsalted butter
- ¾ cup brown sugar
- 1 tablespoon dark corn syrup (light corn syrup will work)
- ⅓ cup heavy cream
- 1 teaspoon vanilla
- 2 teaspoons scotch or bourbon (optional)
- large pinch salt
For the Assembly:
- Chopped pecans or leftover pecan crunch
- Toffee buttercream (recipe to follow)