Preheat your oven to 350°F (180°C). Generously grease a 9x13-inch rectangular pan with butter.
In a blender or food processor, combine the quartered apples with 1/2 cup (480 ml) of the sugar. Pulse a few times to create a puree. You should have about 1 cup (240 ml) of puree.
In a large bowl, whisk together the flour, baking powder, and salt.
In a separate large bowl, use an electric mixer to beat the 1. 5 sticks of softened butter and the remaining 1 cup (240 ml) of sugar until light and creamy.
Add the eggs one at a time, beating well after each addition until the mixture is smooth.
Beat the apple puree into the creamed butter mixture.
Add the dry to the wet in three parts, alternating with the milk. Begin and end with the flour mixture (flour, then milk, flour, then milk, then flour).
Mix gently on low speed until the batter just comes together—be careful not to overmix.
Pour the batter into your prepared pan and spread evenly.
Bake for 45 to 50 minutes, or until the center is set. A gentle press with your finger should leave only a small indentation.
While the cake is baking, prepare your chosen Cake Soak.
Once baked, remove the cake from the oven and let it cool in the pan for about 10 minutes.
Do not remove it from the pan.
Pour the warm cake soak evenly all over the top of the warm cake.
Let it sit and absorb the soak for at least one hour before slicing and serving.
Don't overmix the batter once you combine the wet and dry .
Mix just until the flour streaks disappear to ensure a tender, soft crumb.
