big apple crumb cake

Heat oven: To 325°F (165°C). Lightly coat an 8-inch square or 9-inch cake pan with butter or nonstick spray. For extra security, line it with parchment paper.Prepare apples: Toss apples with lemon juice, then cinnamon and sugar and set aside.Make crumbs: Whisk butter, sugars, cinnamon, and salt together until evenly mixed. Add flour and mix until it disappears. It’s going to be very thick; set it it aside.Make cake: Beat butter with sugar until lightened and fluffy. Add egg, sour cream, and vanilla and beat until combined. Sprinkle surface of batter with with baking powder and salt, and beat well to combine. Add flour and mix only until it disappears.Assemble: Scrape batter into prepared cake pan and smooth it flat. Arrange apples on cake, slightly overlapped. I usually fit all but 2 wedges; those are cook’s snacks. Pour any cinnamon-apple juices in bottom of bowl over apples. Sprinkle crumbs over apple slices. For bigger crumbs, squeeze the crumbs into small fistfuls and break these up into a couple bigger chunks over the cake.Bake: Bake the cake until a toothpick inserted into the apples doesn’t hit any crisp spots and if you look closely, you’ll see juices bubbling around some apples, about 50 to 55 minutes. Cool to room temperature, if you can bear it, before cutting into squares or wedges. Cake keeps at room temperature loosely covered (in an airtight container, the crumbs eventually soften) for 3 days or in the fridge, well-wrapped, for 6 days.