Preheat the oven to 350°F. Prepare a 9x13 inch cake pan by spraying with nonstick cooking spray and then line it with parchment paper.
In a large bowl, add the dry yellow cake mix, eggs, whole milk, vegetable oil, sour cream, and pure vanilla extract. Beat on low speed for 30 seconds, then increase to medium speed and beat for 2 minutes; scraping the bowl as needed.
1 box (13.25 oz) yellow cake mix, 4 large eggs, 1 cup whole milk, 1/2 cup vegetable oil, 1/4 cup full-fat sour cream, 2 teaspoons pure vanilla extract
Spread the batter evenly into the prepared pan. Bake for 20-25 minutes or until the center springs back when lightly touched and a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool in the warm cake pan for 20 minutes. Use the parchment paper to lift the cake out onto a wire cooling rack. Cool completely for 1 hour, then refrigerate for 30 minutes to make it easier to cut.
While the cake chills in the fridge make the whipped cream. In a large bowl, add the heavy whipping cream, powdered sugar, and vanilla extract. Beat on medium-high speed for 3-5 minutes until stiff peaks form and the whipped cream holds its shape. Cover the whipped cream and refrigerate it while you completely the next steps.
3 cups heavy whipping cream, 1 cup powdered sugar, 2 teaspoons pure vanilla extract
Remove the cake from the refrigerator and place it onto a large cutting board or clean countertop. Use a long serrated knife to carefully cut it horizontally, into two thinner layers.
Slide a thin cutting board between the layers, then carefully lift off the top cake layer. Place the bottom cake layer back into the 9x13 cake pan.
Spread the chilled strawberry glaze in a thin, even layer over the bottom layer of cake inside the cake pan. Leaving a 1/2-inch border around the edges.
1 container (13.5 oz) chilled strawberry glaze
Next, evenly spread half of the prepared whipped cream over top the strawberry glaze layer. Carefully place the top cake layer over the whipped cream, without pressing down.
Spread the remaining whipped cream frosting generously over the top cake layer, creating a thick, fluffy layer.
Arrange the sliced strawberries in a single layer over the whipped cream layer.
2 cups sliced fresh strawberries
Cover the cake with a lid or loosely with aluminum foil or plastic wrap, and refrigerate for at least 2 hours before serving (up to 8-12 hours, overnight). *I prefer the flavor and texture of the cake when chilled overnight, this is what I do Serve the cake chilled from the fridge. Enjoy!