Preheat the oven to 350˚F (180˚C). Grease a 12-cup muffin tin with nonstick spray.
2. Step
Transfer one jar of the cookie butter to a microwave-safe bowl. Microwave for 50 seconds, stirring halfway, until warm and loose. Let cool slightly while you prepare the egg mixture.
3. Step
In a large bowl, combine the sugar and eggs. Beat with an electric hand mixer on high speed for 6–8 minutes, until tripled in volume.
4. Step
With a rubber spatula, fold some of the egg mixture into the cookie butter. Gradually fold the cookie butter mixture into the remaining egg mixture (this will help prevent the eggs from deflating) until fully incorporated.
5. Step
Pour the batter into a the prepared muffin tin, dividing evenly.
6. Step
Bake the cakes for 16–18 minutes, until a tester inserted into the center of a cake comes out clean. Remove from the oven and loosen the edges of each cake with an offset spatula or butter knife, then invert the pan onto a wire rack.
7. Step
Add the remaining jar of cookie butter to a microwave-safe bowl and microwave for 50 seconds, stirring halfway, until melted. Drizzle over the cakes.
