Make the ice cream: Preheat oven to 350 degrees. Toss walnuts with honey and salt on a parchment-lined baking sheet, and spread evenly. Bake, stirring every 3 minutes, until nuts are toasted and crisp, 10 to 12 minutes. Let cool.
Fold honeyed walnuts into ice cream or sorbet in a bowl. Freeze until just firm, at least 1 hour (or up to 3 days; soften slightly before serving.)
Make the meringues: Raise oven temperature to 375 degrees. Pulse walnuts, sugar, cinnamon, and salt in a food processor until nuts are finely ground.
With a mixer fitted with the whisk attachment, beat egg whites with cream of tartar until stiff peaks form. Fold walnut mixture into whites in 2 additions.
Using a pastry bag fitted with a 1/2-inch plain pastry tip (such as Ateco #806), pipe walnut mixture into sixteen 2 1/2-inch rounds on parchment-lined baking sheets, spacing them 1 inch apart.
Bake, rotating sheets halfway through, until deep gold, 14 to 16 minutes. Let cool completely on sheets on a wire rack. (Meringues can be stored in an airtight container for up to 2 days.)
Make the apples: Bring honey to a boil in a medium saute pan over medium-high heat. Cook until amber and fragrant, about 4 minutes. Add butter or margarine and salt, reduce heat to medium, and swirl pan until butter melts. Add apples, and cook, stirring occasionally, until tender, about 5 minutes. Let cool in pan for 10 minutes.
Assemble dacquoises: Place 1 meringue, flat side up, in each dish. Top with 1 scoop of ice cream and some of the apple slices. Drizzle with sauce from pan. Top with remaining meringue, shiny side up. Serve immediately.