"Hasselback" refers to accordion-style slices, a method often used on potatoes in savory dishes. Try here with apples to create lots of little crevices for cinnamon, sugar and ice cream. You haven't had apples à la mode until you've had them Hasselback-style. Just make sure you pick the right apples — here's how to tell.
Cut apples in half lengthwise and place apple half cut side down on a work surface.
Put a chopstick on either side of an apple half. Using a small paring knife, cut the apple crosswise in 1/8-inch intervals, cutting down until the knife hits the chopstick (this will prevent you from cutting all the way through). Repeat with remaining apple halves and arrange them peel side up in a large ceramic baking dish.
In small saucepan, melt butter with cinnamon, brown sugar and salt, then spoon it between the slices of the apple. Drizzle any remaining butter on top. Cover the baking dish with foil.
Bake the apples in a covered baking dish at 375°F for 30 minutes, then uncover and bake again for 15 minutes, until tender and lightly browned. Let cool for 5 minutes.
Serve with vanilla ice cream.