Preheat your oven to 350°F and line an 8×8-inch pan with parchment paper.
In a medium bowl, mix 1 cup almond flour, 1/2 cup vanilla protein powder if using (If omitting protein powder, use 1 additional cup almond flour), 3 tablespoons melted coconut oil, 2 tablespoons maple syrup, 1 to 2 tablespoons milk, 1 teaspoon vanilla extract, and 1/4 teaspoon salt until a thick, cookie-style dough forms. Press the dough evenly into the pan.
Bake for 10 to 11 minutes, just until the edges are lightly golden. Let the shortbread base cool before adding the next layer.
In a small saucepan over low heat, combine 2/3 cup cashew butter, 1/3 cup maple syrup, 1/4 cup coconut oil, 1 teaspoon vanilla extract, and 1/4 teaspoon salt. Stir gently until smooth and fully combined.
Pour the warm caramel over the cooled shortbread and spread it evenly. Let the pan cool on the counter for about 10 minutes, then place it in the freezer for at least 30 minutes until the caramel layer is firm.
In a microwave-safe bowl, melt 2/3 cup chocolate chips with 1 1/2 tablespoons coconut oil, stirring every 30 seconds until smooth.
Pour the melted chocolate over the set caramel layer and spread it evenly. Sprinkle lightly with flaky sea salt if you like. Place the pan in the fridge for about 10 minutes until the chocolate is set, then slice into bars.Store the bars in the fridge or freezer for the best texture.