Whisk oats, almond milk, coconut milk, 1/2 cup coconut flakes, sliced almonds, chia seeds and coconut extract together in a large bowl until combined. Refrigerate, uncovered, until set and thickened, about 1 hour.

Stir chocolate chips and coconut oil together in a small microwave-safe bowl. Microwave on High until the chocolate is melted, 45 to 60 seconds; stir until the chocolate chips are completely melted and incorporated into the oil.

Divide the oat mixture among 4 (8-ounce) jars, about 1 cup each. Dip whole almonds in the melted chocolate, stirring to coat. Lift and let excess chocolate drip back into the bowl; place the coated almonds on a small parchment-paper-lined plate and refrigerate. Spoon about 2 teaspoons of the melted chocolate over each jar, tilting to cover the entire surface. Refrigerate, uncovered, until the chocolate layer is just set, about 10 minutes. Top each jar with 1 chocolate-coated almond. Sprinkle with flaky salt and the remaining 1 teaspoon coconut flakes; cover and refrigerate until the oatmeal has thickened and the chocolate layer is fully set, at least 12 hours or up to 4 days.