In a small bowl, combine instant pudding and milk with a fork until smooth and beginning to thicken.

Stir in crushed cookies and mix to combine.

Set aside to stand at room temperature; filling should thicken to a pudding consistency.

In a small saucepan, combine chocolate chips and pareve milk over low heat, stirring until chips are melted and mixture is smooth. Remove from heat.

Add remaining cake ingredients and stir until batter is smooth.

Pour batter into prepared ramekins, filling about halfway. Add two tablespoonfuls of pudding filling to the center of each ramekin.

Divide the remaining batter evenly among the six ramekins, making sure to completely cover the pudding filling. The cakes will not rise very much during baking, so if they’re pretty full, it’s fine.

Place the ramekins on a baking sheet and bake for 17–18 minutes, or until the cakes are just set; remove from oven.

Invert cakes onto small dessert plates, drizzle with chocolate liqueur or syrup if desired, and garnish with crushed sandwich cookies.

Meanwhile, preheat oven to 350 degrees Fahrenheit (180 degrees Celsius). Prepare six four-ounce (110-gram) ramekins by spraying with cooking spray and dusting with flour; tap out excess flour.