Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan, ensuring it's well coated.

In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.

In a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment, cream the softened unsalted butter and granulated sugar together on medium speed until the mixture is light, fluffy, and pale in color (about 3-5 minutes).

Beat in the eggs one at a time, ensuring each egg is fully incorporated before adding the next. Scrape down the sides of the bowl as needed. Stir in the vanilla extract.

With the mixer on low speed, alternately add the flour mixture and the whole milk to the butter mixture, beginning and ending with the flour mixture (e.g., 1/3 flour, 1/2 milk, 1/3 flour, 1/2 milk, 1/3 flour). Mix until just combined and no streaks of flour remain. Be careful not to overmix.

Pour the batter evenly into the prepared 9x13 inch baking pan. Bake for 45-50 minutes, or until a wooden skewer or toothpick inserted into the center of the cake comes out clean.

Let the cake cool completely in the pan on a wire rack. Once fully cooled, carefully invert it onto a cutting board and cut the cake into approximately 1-inch cubes.

In a medium bowl, combine the hulled and sliced fresh strawberries with the granulated sugar and optional fresh lemon juice.

Gently toss the strawberries to coat them evenly with the sugar. Let the mixture sit at room temperature for at least 30 minutes (or refrigerate for up to 2 hours), stirring occasionally, until the berries release their sweet, flavorful juices.

Ensure your heavy cream is very cold. For best results, chill your mixing bowl and whisk attachment (if using a stand mixer) in the freezer for 10-15 minutes before starting.

Pour the cold heavy cream into the chilled bowl. Beat on medium-high speed (using a stand mixer or hand mixer) until soft peaks begin to form.

Gradually add the powdered sugar and vanilla extract. Continue beating until stiff peaks form, meaning the cream holds its shape when the whisk is lifted. Be careful not to overbeat, as it can turn granular.

Begin assembling your trifle in a large, clear trifle bowl (approximately 3-4 quart capacity). Arrange one-third of the cooled pound cake cubes in an even layer at the bottom of the bowl.

Spoon one-third of the macerated strawberries (including their delicious juices) evenly over the cake layer.

Carefully spread one-third of the vanilla whipped cream over the strawberry layer, ensuring a smooth, even coating.

Repeat these layers twice more: another layer of cake cubes, followed by strawberries and their juices, and then whipped cream. Finish with a final layer of whipped cream on top.

Optionally, garnish the top of the trifle with a few whole strawberries and fresh mint sprigs for an elegant presentation.

Cover the trifle loosely with plastic wrap and refrigerate for at least 2 hours. This chilling time is crucial as it allows the flavors to meld beautifully and the cake to absorb some of the strawberry juices, creating a wonderfully moist texture.

Serve the Strawberry Shortcake Trifle chilled directly from the trifle bowl.