Strawberry Shortcake Bar Cake – Ultimate Moist Grocery-Store Version

• Hot Milk Butter Sponge Sheet Cake (Rich, Flexible, Moist)
• 4 large eggs, room temperature
• 100g (1/2 cup/100ml) white sugar
• 1 tsp vanilla extract
• 100g (3/4 cup + 1 tbsp) cake flour
• 1/2 tsp baking powder
• 1/4 tsp salt
• 40g (3 tbsp) unsalted butter
• 30ml (2 tbsp) whole milk
• *Optional:* 1 tsp corn syrup or 1 tsp glycerin (for added moisture retention)
• Moisture Syrup (Simple Syrup)
• 1/4 cup (50g) white sugar
• 1/4 cup (60ml) water
• *Optional:* a drop of vanilla or strawberry extract
• Strawberry Filling (Preserve-Like with Nostalgic Vibe)
• 250g (1¾ cups/275ml) frozen strawberries
• 2½ tbsp sugar
• 1 tsp lemon juice
• 2 tsp cornstarch mixed with 1 tbsp (15ml) cold water (slurry)
• 1/2 tsp strawberry extract, optional
• 1/2 tsp vanilla extract
• *Optional:* 1 tsp strawberry Jell-O powder (to be dissolved in hot water per instructions)
• Stabilized Whipped Cream Filling
• 480ml (2 cups) cold heavy cream
• 3 tbsp powdered sugar
• 1 tsp vanilla extract
• 2 tbsp skim milk powder *(or 1 tsp gelatin bloomed in 1 tbsp/15 ml water)*

Instructions

1. 1

   Preheat the oven to 340°F (170°C). Line your 13x18" (33x46cm) sheet pan with parchment paper.

2. 2

   In a bowl, melt the butter and milk together until steaming (not boiling). Keep warm.

3. 3

   In another large bowl, beat the eggs, sugar, and vanilla on high speed for 6–8 minutes, until pale, thick, and tripled in volume.

4. 4

   Sift in the flour, baking powder, and salt in 2 additions. Gently fold with a spatula just until incorporated.

5. 5

   Drizzle the warm butter-milk mixture (and corn syrup or glycerin, if using) around the sides of the bowl. Fold gently but completely. Target: 120–130°F (49–54°C) (hot to the touch, but not scalding).

6. 6

   Pour the batter into the sheet pan and spread evenly. Tap once to release air.

7. 7

   Bake 8–12 minutes, until the top is pale golden and springs back to the touch. The cake is done when the surface is set and dry to the touch, the cake springs back lightly when pressed in the centre, and the colour is even and very pale golden—not deeply browned.

8. 8

   Cool in the pan for 5 minutes, then remove to a rack to cool completely. Chill for 30+ minutes for easier slicing.

9. 9

   Heat the sugar and water in a small pan until dissolved. Cool fully. Brush a thin layer over each sponge layer after slicing.

10. 10

    Simmer the berries, sugar, and lemon juice until soft (5–7 minutes). The critical step is to soften them, not reduce them! Cooking too much could result in berries being too firm. Mash lightly or blend if you want a smoother texture. Add the slurry and simmer until glossy and thick (2–3 minutes). Off the heat, stir in the Jell-O liquid (made by dissolving 1 tsp (5ml) powder in 1 tbsp (15ml) hot water). Cool fully before using.

11. 11

    Whip the cream, sugar, vanilla, and milk powder to firm peaks. (If using gelatin, beat to soft peaks, drizzle in the cooled gelatin, then whip to firm peaks.) Chill until ready to use.

12. 12

    Slice the chilled sponge cake into three rectangles. (Trim the edges to clean up if needed.) Place the bottom sponge layer on a plastic-wrap-lined tray. Lightly brush with simple syrup. Spread a thin layer of strawberry preserve, then about ¼" (0.6cm) of whipped cream. Repeat with the second layer. Add the final sponge layer, syrup-brushed. Gently press down. Wrap and chill for 4+ hours or overnight to set the layers.

13. 13

    Trim the edges for a clean finish. Slice with a hot, dry knife. Decorate the top with piped cream, strawberries, or white chocolate shavings (optional).

14. 14

    Preheat the oven to 340°F (170°C). Line the pan carefully.

15. 15

    In a stand mixer, beat the eggs, sugar, and vanilla on high speed for 8–10 minutes—until very thick, pale, and at full ribbon stage (must at least triple in volume).

16. 16

    In 3 additions, sift the flour and salt over the batter. Fold gently after each addition, keeping the volume.

17. 17

    If using, fold in the water and oil mixture very gently at the end.

18. 18

    Pour into the pan, level carefully, and bake for 12–15 minutes.

19. 19

    Cool as before.