1. Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan with butter or cooking spray. Line the bottom of the pan with parchment paper for easy removal.
2. Mix Dry Ingredients: In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, and salt until well combined. If using citrus zest, add it to the dry ingredients and mix until evenly distributed.
3. Combine Wet Ingredients: In a separate bowl, whisk together the plain Greek yogurt, vegetable oil, eggs, and vanilla extract until smooth and creamy.
4. Combine Wet and Dry Ingredients: Pour the wet ingredients into the dry ingredients and gently fold them together using a spatula or wooden spoon until just combined. Be careful not to overmix, as this can result in a dense cake.
5. Bake the Cake: Pour the cake batter into the prepared cake pan and smooth the top with a spatula. Tap the pan gently on the counter to remove any air bubbles. Place the pan in the preheated oven and bake for 25-30 minutes, or until a toothpick inserted into the center of the cake comes out clean.
6. Cool and Serve: Remove the cake from the oven and let it cool in the pan for 10 minutes. Run a knife around the edge of the cake to loosen it, then carefully invert it onto a wire rack to cool completely.
7. Optional: Glaze or Frosting: Once the cake has cooled, you can optionally drizzle it with a simple glaze made from powdered sugar and lemon juice, or frost it with your favorite cream cheese frosting for added indulgence.
8. Slice and Enjoy: Slice the creamy yogurt cake into wedges and serve it with a dollop of whipped cream or a scoop of vanilla ice cream, if desired. Enjoy the creamy texture and delightful flavor of this irresistible dessert.

Tips for Success:

• Use full-fat Greek yogurt for the creamiest texture and richest flavor.
• Feel free to customize the cake by adding fresh fruit, nuts, or chocolate chips to the batter before baking.
• Store any leftovers in an airtight container at room temperature for up to 3 days, or in the refrigerator for longer storage.