Heat oven to 375°F (190°C).
Prepare pan by coating the short ends of a loaf pan with butter or nonstick spray and lining the bottom and two long sides with parchment paper.
Place the loaf pan on a rimmed baking sheet.
Peel and core the apples, then slice them very thin (about ⅛-inch or ⅓-cm thick) and toss with lemon juice.
Melt butter in a medium bowl, then whisk in sugar and salt, followed by eggs and vanilla until evenly incorporated.
Whisk in flour until smooth, then add milk.
Pour batter over sliced apples and stir to coat evenly.
Push about a dozen full slices to the side for the final layer and arrange the remaining apple slices slightly overlapped around the prepared loaf pan.
Pour the remaining batter over the apples and level it out.
Tap the pan on the counter to release any trapped air bubbles and decorate the top with apple slices if desired.
Bake for 60 to 70 minutes, or until a toothpick comes out clean.
Transfer to a cooling rack for 5 minutes, then brush the top with warmed apricot preserves and let cool completely in the pan.
Once cooled, loosen the cake from the pan and transfer to a serving plate. Dust with powdered sugar if using.
