01 -
Heat the oven to 350°F. Grease or line a 9-by-9-inch square pan, and separate the cake, topping and drizzle ingredients.
02 -
Cream the cake’s softened butter and granulated sugar until visibly lighter. Beat in eggs one at a time, then vanilla. Separately combine the cake flour, baking powder and salt; mix into the butter mixture just until combined, then fold in evenly diced apples.
03 -
Spread the thick batter across the prepared pan, reaching the corners without leaving a mound in the middle.
04 -
Combine topping flour, cinnamon, salt and both topping sugars. Work in the cold cubed butter with a cutter or fingertips until coarse crumbs form; avoid warming it into a paste.
05 -
Scatter crumbs evenly. Bake about 30–45 minutes, checking the center in several places for set cake rather than raw batter. Shield the topping if it darkens first; continue as needed.
06 -
Gently heat the drizzle butter, brown sugar, cinnamon, milk and salt in a small saucepan, stirring until smooth. The sauce contains no apple ingredient.
07 -
Let the cake cool enough to hold together before cutting. Spoon warm drizzle over portions, keeping any remaining sauce separate for later serving.