Step 1: Preheat and Prep

• Preheat your oven to 350°F (175°C).
• Have an ungreased 10-inch tube pan ready (do not grease, as chiffon cakes need to cling to the pan to rise).

Tip: Use a tube pan with a removable bottom for easy cake release.

Step 2: Make the Cake Batter

• In a large bowl, combine 1 ¾ cups cake flour, 1 tablespoon baking powder, 1 teaspoon salt, and ½ cup white sugar.
• Add ½ cup vegetable oil, 6 egg yolks, ¾ cup water, and 1 tablespoon lemon zest. Beat with an electric mixer until smooth, about 1-2 minutes.

Tip: Ensure the yolk mixture is well-blended for a uniform batter.

Step 3: Whip the Egg Whites

• In a separate clean, grease-free bowl, beat 6 egg whites with ½ teaspoon cream of tartar using an electric mixer until soft peaks form.
• Gradually add ¾ cup white sugar, beating until very stiff and shiny peaks form, about 3-5 minutes.
• Gently fold ⅓ of the egg whites into the yolk batter to lighten it, then quickly fold in the remaining whites until no streaks remain, being careful not to deflate the mixture.

Tip: Use a rubber spatula and a gentle folding motion to maintain the airy texture.

Step 4: Bake the Cake

• Pour the batter into the ungreased 10-inch tube pan, spreading it evenly.
• Bake for 1 hour, or until a toothpick inserted in the center comes out clean.
• Immediately invert the pan (place it upside down on a bottle or wire rack) and let the cake cool completely, about 1-2 hours.
• Once cool, run a knife around the edges and center tube to loosen, then remove the cake from the pan.

Tip: Inverting the cake prevents it from collapsing as it cools.

Step 5: Make the Filling

• In a chilled glass or metal bowl, beat 1 cup heavy whipping cream with an electric mixer until soft peaks form, about 2-3 minutes.
• Gently fold in 2 ½ cups lemon pie filling until well combined and the mixture is stiff.
• Chill the filling in the refrigerator for 15-30 minutes to firm up.

Tip: Chill the bowl and beaters beforehand for faster whipping and a firmer cream.

Step 6: Assemble the Cake

• Using a serrated knife, carefully slice the cooled cake horizontally into 3 equal layers.
• Spread ⅓ cup of the lemon filling evenly over the bottom layer, leaving a slight border.
• Place the second layer on top and spread another ⅓ cup filling. Top with the third layer.
• Spread the remaining filling over the top of the cake, smoothing it out.
• Decorate with 8 thin lemon slices, if using, for a fresh, elegant touch.

Tip: Slice the cake slowly and evenly to ensure uniform layers.

Step 7: Chill and Serve

• Refrigerate the assembled cake for at least 1 hour to set the filling.
• Slice into 14 pieces and serve chilled for the best texture.

Tip: Use a sharp knife dipped in hot water for clean slices through the creamy filling.