Toss the apples with the lemon juice in a medium bowl, sprinkle on the cinnamon and sugar, toss again and set aside.

Preheat the oven to 325, butter a 9 x 9 cake pan, line it with parchment so that there are 2 overhanging handles and butter the parchment.

To prepare the crumbs, whisk together the butter, both sugars, cinnamon and salt and then use a stiff spatula to work in the flour until it disappears.  Set it in the fridge until you need it and keep the spatula handy, you’re going to need it to break it up again into chunks.

For the cake, use your electric mixer to beat together the butter and sugar for a couple of minutes until lighter in color and fluffy.  Add in the egg, sour cream and vanilla and beat again until well combined.  Sprinkle on the baking powder and salt, beat again, and then finally add the flour and mix only until no trace of flour can be seen.

Assemble the cake!  Scrape the batter evenly across the bottom of your prepared pan and smooth out the top.  Use your hands (easiest) to overlap the apple slices evenly across the top and then scrape and pour any juices that accumulated evenly over all.  Break up the crumbs if needed and generously and thickly layer on the crumb mix and give it a gentle pat so that it’s as even as possible.

Bake the cake for 50 to 55 minutes – this is a tough one to tell when it’s done but there should be juices bubbling around all of the apples and the center will be set.

Allow the cake to cool in the pan for an hour or so before attempting to lift it out onto a cutting board to slice.  This is a heavy (yummy) pound-like apple cake that would also be lovely served in small slices for a brunch.