Step 1: Prepare the Baking Pan

1. Preheat your oven to **170°C / 350°F**.
2. Line a 20×20 cm or 8×8 inch baking pan with parchment paper. This makes it easier to lift the cake out after baking.

Step 2: Mix Sugar and Lemon Zest

1. Add the sugar and lemon zest to a mixing bowl.
2. Rub them together with your fingers for a few seconds. This helps release the lemon oils from the zest and makes the cake more fragrant.
3. This small step gives the cake a stronger fresh lemon flavor.

Step 3: Cream the Butter and Sugar

1. Add the softened butter to the lemon sugar.
2. Cream the butter and sugar together for about **2 minutes**, or until the mixture becomes light and creamy.

Step 4: Add the Oil

1. Add the vegetable oil and whisk for about **1 minute** until everything is well combined.
2. The oil helps keep the cake moist and soft.

Step 5: Add the Eggs and Vanilla

1. Add the eggs and whisk for about **2 minutes**.
2. Scrape down the sides of the bowl if needed so everything mixes evenly.
3. Add the vanilla extract and mix again.

Step 6: Add the Yogurt

1. Add the natural yogurt and whisk for about **1 minute** until the batter looks smooth.
2. The yogurt helps make the cake tender and keeps it from becoming dry.

Step 7: Add Flour and Baking Powder

1. Sift the plain flour and baking powder directly into the same bowl.
2. Gently fold the mixture by hand using a spatula.
3. Do not overmix. Mix only until the flour disappears into the batter.

Step 8: Add Lemon Juice

1. Add the lemon juice and whisk on low speed for about **15 seconds**.
2. Then give the batter one final gentle mix with a spatula to make sure everything is evenly combined.

Step 9: Bake the Cake

1. Pour the batter into the lined baking pan and spread it evenly.
2. Bake at **170°C / 350°F** for **30 to 35 minutes**, or until a skewer inserted into the center comes out clean.
3. The cake should be lightly golden on top.

Step 10: Poke the Cake

1. While the cake is still warm, poke holes all over the top using a skewer, chopstick, or the handle of a spoon.
2. Do not poke all the way through the cake. Just make enough holes so the lemon curd can sink in.

Step 11: Add Lemon Curd

1. Warm the lemon curd slightly if it is too thick, then spread or pour it over the warm cake.
2. Let the lemon curd settle into the holes and cover the top.
3. You can serve the cake warm, or let it cool completely before slicing.