Step 1

Beat mascarpone, cream cheese, and pudding mix with a stand mixer fitted with a paddle attachment on medium speed until fluffy, about 2 minutes. Beat in milk and lemon extract on low speed until combined, about 1 minute. Increase speed to medium-high, and beat until mixture is smooth, light, and fluffy, 2 to 3 minutes.

Step 2

Combine lemon juice and sugar in a medium-size microwavable bowl; microwave on HIGH 20 seconds. Whisk until sugar has dissolved. Dip 8 ladyfingers in lemon juice mixture, and arrange in a single layer in an 8-inch square baking dish. Spread one-third of pudding mixture evenly over ladyfingers in baking dish, and smooth with a spatula. Repeat layering process 2 times to yield 3 layers until all ladyfingers and pudding mixture have been used.

Step 3

Smooth top layer of pudding mixture with a spatula, and sprinkle evenly with lemon zest. Cover and refrigerate at least 2 hours or up to 24 hours before serving. Let stand at room temperature for 30 minutes before serving.