Instructions

MAKE THE IMPROVED LEMON POPPY SEED CAKE:
1. Preheat oven to 350°F (175°C). Grease 9x13-inch baking pan and line with parchment paper, leaving overhang on two sides for easy removal.
2. In medium bowl, sift together all-purpose flour, baking powder, and salt to ensure even distribution and aeration.
3. Stir poppy seeds into flour mixture and set aside.
4. In large bowl using electric mixer, cream softened butter and granulated sugar together on medium-high speed until very light, fluffy, and pale in color, about 5 minutes (extended creaming is essential for tender texture).
5. Beat in eggs one at a time, mixing well after each addition and scraping down bowl sides between additions to ensure even incorporation.
6. Add increased lemon zest from 3 lemons, fresh lemon juice, vanilla extract, and lemon extract, mixing until well incorporated.
7. In small bowl, whisk together whole milk with sour cream until smooth (sour cream is key correction for tender texture).
8.Add flour mixture in three additions alternating with milk-sour cream mixture: one-third flour, half milk mixture, one-third flour, remaining milk mixture, remaining flour.
9. Mix on low speed just until combined after each addition, scraping down bowl as needed (do not overmix to prevent tough sponge).
10. Pour batter into prepared pan and spread evenly to all edges and corners using offset spatula.
11. Tap pan gently but firmly on counter 2-3 times to remove air bubbles and ensure even distribution throughout.
12. Place pan on center rack of oven and bake 30-35 minutes, rotating pan 180 degrees halfway through at approximately 17 minutes for even browning.
13. Test for doneness by inserting toothpick in both center and near edges - should come out clean or with just a few moist crumbs throughout.
14. Cake should spring back when lightly touched in center and pull slightly from pan sides with golden brown edges.

APPLY LEMON SYRUP:
15. While cake bakes, combine fresh lemon juice, granulated sugar, and water in small saucepan.
16. Heat over medium heat, stirring constantly, until sugar completely dissolves.
17. Bring to gentle simmer and cook for 2 minutes to create light syrup consistency (should be slightly thickened but still pourable).
18. As soon as cake comes out of oven while still very hot, use wooden skewer to poke holes all over surface, spacing about 1 inch apart and going halfway through cake depth (about 30-40 holes total).
19. Using pastry brush, brush hot lemon syrup generously and slowly over hot cake, allowing syrup to absorb completely before adding more (use all syrup).
20. Allow cake to cool completely in pan on wire rack, about 1 hour, allowing syrup to fully soak in.

MAKE THE WHITE CHOCOLATE MASCARPONE TOPPING:
21. Melt chopped white chocolate gently in microwave in 30-second intervals, stirring between each interval, or in double boiler, stirring until completely smooth.
22. Allow melted chocolate to cool to room temperature (about 85°F/29°C), approximately 15-20 minutes, stirring occasionally.
23. In medium bowl using electric mixer, beat room temperature mascarpone cheese with powdered sugar until smooth and creamy with no lumps.
24. In separate clean bowl with clean beaters, whip heavy cream to soft peaks (peaks should bend slightly when beaters are lifted).
25. Gently fold cooled white chocolate into mascarpone mixture using rubber spatula until well combined and smooth.
26. Fold whipped cream into mascarpone-chocolate mixture in two additions, using gentle folding motion to maintain airiness.
27. Fold in vanilla extract and lemon zest until evenly distributed.

FINAL ASSEMBLY:
28. Once cake is completely cool to touch, spread white chocolate mascarpone topping over entire surface using offset spatula, creating smooth, even layer.
29. Sprinkle extra lemon zest and additional poppy seeds decoratively over topping.
30. Optional: Arrange candied lemon slices on top for elegant presentation.
31. Chill traybake in refrigerator for at least 30 minutes to set topping before cutting.
32. Using sharp knife, cut into 16 even pieces (make 3 lengthwise cuts to create 4 rows, then make 3 crosswise cuts to create 4 columns).
33. Wipe blade clean with damp cloth between each cut to maintain neat edges.
34. Serve at room temperature or slightly chilled, with each piece showcasing tender, moist, flavorful cake with visible poppy seed specks and creamy topping.

STORAGE AND SERVING:
Store covered in refrigerator up to 4 days (topping requires refrigeration)
Best served at cool room temperature - remove from refrigerator 15-20 minutes before serving
Can be made 1 day ahead and refrigerated overnight
Unfrosted cake can be frozen wrapped tightly for up to 2 months (thaw completely before topping)
Keep refrigerated and covered to maintain freshness and prevent topping from softening