Caramel Apple Blackout Cake

I'm in love with a dessert blog that's not Smitten Kitchen. Often, I look at a recipe on Desserts for Breakfast and think it looks nothing short of amazing, but then I realize that even with my craziness, I don't have the patience to make it. I couldn't resist this recipe when I first saw it and it was only after a couple of reads that I even realized it's a vegan recipe. I de-veganized slightly (who could pass on butter? and I just couldn't bring myself to buy almond milk, although I think it might make this even better). This recipe wasn't as sweet as I imagined it from the pictures, but it certainly disappeared quickly. Definitely worth making.

Caramel Apple Blackout Cake (from Desserts for Breakfast)

Ingredients
2 large tart apples (e.g., Granny Smith)
1/4 cup sugar
2 Tbspn water
2 Tbspn butter
coarse sea salt
1 cup milk
1 tspn apple cider vinegar
1 cup whole wheat flour
1/3 cup Dutch-processed cocoa powder
1 tspn cinnamon
1 tspn baking powder
1 tspn baking soda
1/2 cup sugar
1/3 cup vegetable oil
2 tspn vanilla extract

1. Grease and flour the bottom and sides of a 7" round cake pan (with at least 2" tall sides). Line the bottom with a piece of parchment paper and grease again.
2. Peel, core, and slice the apples into chunks about 1/8-1/4" thick. Set aside.
3. In a light-colored saucepan (preferably with tall sides), combine the sugar and water. Stir to make sure the sugar is completely damp.
4. Over high heat, cook the sugar, without stirring but swirling the pan, until it reaches a light golden caramel color. Remove from heat immediately and stir in the butter until the caramel is smooth. Be careful--the mixture will sputter!
5. Pour the caramel into the bottom of the prepared cake pan and sprinkle generously with coarse sea salt. Then, line the bottom with apple chunks, packing them in as tight as possible.
6. Preheat the oven to 350 degrees F. If desired, line the outside of the cake pan with bake-even strips.
7. In the mixer bowl, combine the almond milk and cider vinegar, stirring briefly. Let sit for a few minutes until the milk is curdled.
8. Meanwhile, sift together the whole wheat flour, cocoa powder, cinnamon, baking powder, and baking soda in a separate bowl.
9. Once the milk is curdled, add the sugar, vegetable oil, and vanilla extract to the mixer bowl and beat until frothy.
10. Add the dry ingredients to the wet in two stages, beating thoroughly between each addition. After the final addition, beat the batter until smooth but do not overmix.
11. Pour the batter over the the apples in the prepared pan and tap the cake pan gently against the counter to allow the batter to settle.
12. Bake in the oven for 40-50 minutes, until set and the top of the cake springs back when gently touched. (If you use the toothpick test, be forewarned that the toothpick won't come out completely clean when the cake is done.)
13. Remove the cake from the oven and let cool on a cooling rack for ten minutes. Then, turn the cake out of the pan. (Don't forget to do this, as inverting the cake will allow the caramel to soak down into the cake!) Serve warm or at room temperature.