Preheat the oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.

In a mixing bowl, combine the yellow cake mix, eggs, water, and vegetable oil. Mix until well combined.

Pour the batter into the prepared baking pan and smooth the top.

Bake for 30 minutes or until a toothpick inserted in the center comes out clean.

Remove from the oven and let cool for 10 minutes.

While the cake is still warm, use a toothpick to poke holes all over the top of the cake.

In a small bowl, mix the blueberry syrup and lemon juice. Pour this mixture evenly over the cake, allowing it to soak in.

In a mixing bowl, whip the heavy cream until soft peaks form. Gradually add the powdered sugar and vanilla extract, continuing to whip until stiff peaks form.

Spread the whipped cream over the top of the cake. Garnish with fresh blueberries and lemon zest.

Chill the cake in the refrigerator for at least 1 hour before serving. Slice and enjoy!