Place the chocolate chips in a microwave-safe bowl and heat in 30-second intervals, stirring in between, until fully melted and smooth. You can also use a double boiler on the stovetop for a slower, more controlled melt.
Line a baking sheet with parchment paper. Pour the melted chocolate onto the paper and spread into a rectangle about 1/4-inch thick using a spatula. Try to keep the edges clean and even for easy breaking later.
Melt the caramel bits with the milk in a separate bowl until smooth. Drizzle the caramel over the chocolate base using a spoon or piping bag. Scatter chopped dried apples and nuts on top, pressing them lightly into the chocolate. If using, drizzle with melted white chocolate and sprinkle with flaky sea salt.
Place the bark in the refrigerator for at least 1 hour, or until fully set. Once firm, break into pieces using your hands or a sharp knife. Store in an airtight container.