Preheat your oven to 350°F (175°C). Grease and flour your cake pan to prevent sticking. Gather all your ingredients for an easy start.
In a large mixing bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, and salt until well combined. This ensures even distribution of the dry ingredients.
Add the eggs, vegetable oil, and vanilla extract to the dry mixture. Whisk vigorously until the batter is smooth, shiny, and free of lumps. It should have a rich, chocolatey aroma.
Fold in the chopped strawberries gently using a spatula, distributing them evenly without deflating the batter. The strawberries will add colorful bursts throughout the cake.
Pour the batter into the prepared cake pan, smoothing the top with the spatula for an even surface. Tap the pan lightly on the counter to remove air bubbles.
Bake in the preheated oven for about 35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. The cake will develop a deep, rich color and a fragrant cocoa smell.
Remove the cake from the oven and transfer to a cooling rack. Let it rest for at least 15 minutes to set and cool slightly, making it easier to slice without breaking.
Gently run a knife around the edges of the cake to loosen it, then carefully invert onto a plate or serving platter. Allow it to cool completely if decorating or serving later.
Slice the cake to reveal vibrant red strawberries embedded in the rich cocoa crumb. Serve on plates, and enjoy the moist, tender texture with bursts of fruity sweetness.