Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan with butter or cooking spray and line the bottom with parchment paper.

In a large mixing bowl, whisk together the Greek yogurt, eggs, sugar, vegetable oil, and vanilla extract until smooth and well combined.

In a separate bowl, sift together the flour, baking powder, and salt. Add lemon zest if using.

Gently fold the dry ingredients into the wet ingredients using a spatula. Mix until just combined, being careful not to overmix. The batter should be smooth and thick.

Pour the batter into the prepared cake pan and smooth the top with a spatula to ensure even baking.

Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean and the top is golden brown.

Remove from oven and let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Dust with powdered sugar before serving if desired.