Preheat oven to 350 degrees. Cut parchment paper to fit the bottom of a 9"round cake pan. Grease the sides of the pan.In a large mixing bowl add the eggs and granulated sugar. Beat on high until the mixture is foamy and light yellow. Carefully add the flour and fold into the mixture with a wooden spoon. Pour batter into prepared pan. Bake for 25 minutes. Cool
In a small bowl add the lemon pudding and the milk. Follow instructions on the box.
Pour the whipping cream into a chilled mixing bowl. Beat on high for 1 minute. Turn to med speed and slowly add the powdered sugar. Once the powdered sugar is added, turn the speed back up to high and beat until a stiff peak forms when dipping the beater into the cream and pulling up.
When the cake is cooled, cut the cake in half horizontally than cut into 1" squares. Using a trifle bowl or large bowl add a layer of the cut cake to cover the bottom, add a layer of the pudding followed by blueberries then top with whipped cream. Repeat 3 times.Garnish the top with blueberries and lemon slices if desired. Cover with plastic wrap and let sit in the fridge for at least 2 hours to allow the flavors to meld. Serve and enjoy! Store remaining cake in the refrigerator.