Make the cake: Arrange a rack in the middle of the oven and heat to 350°F. Coat a 13x18-inch rimmed baking sheet (also known as a half sheet pan) with cooking spray; set aside.Whisk the flour, sugar, baking powder, and salt together in a large bowl. Add the eggs, oil or butter, milk, and vanilla and mix with an electric hand mixer on medium speed until smooth, about 3 minutes.Pour the batter into the baking sheet. Bake until the cake is lightly browned and springs back when gingerly pressed with a finger, 20 to 25 minutes. Cool the cake on a wire rack while preparing the strawberries.

Make the strawberry filling: Place all the ingredients together in a large bowl and toss to combine. Set aside for 30 minutes at room temperature.

Use a 3-inch round cutter to cut the cooled cake into 24 rounds.

Make the whipped cream: Place all ingredients in a large bowl. Beat with an electric hand mixer on medium-high speed until stiff peaks form.

To assemble each shortcake, place 1 cake round on a plate. Top with a scoop of strawberries and a generous dollop of whipped cream. Finish with a second cake round.