Pistachio Cake in a 9x13 Pan

Pistachio cake in a 9×13 pan starts with one box of white cake mix and one 3.4-ounce box of instant pistachio pudding mix, plus 3 eggs, 3/4 cup of oil and 1 cup of club soda, baked at 350°F for 35 to 40 minutes. A fluffy pistachio pudding frosting goes on top once the cake is cold, and chopped pistachios finish it.

This is the pale green, nut-flecked sheet cake that shows up at potlucks and holiday buffets. The pudding mix gives it both its color and a soft, moist crumb that stays tender for days in the refrigerator.

Why This Recipe Fits a 9×13 Pan

One box of cake mix is designed for a 9×13 pan, and adding the pudding mix and soda makes the batter a little heavier and taller, so it fills the pan just over halfway. The frosting is made to cover exactly one 9×13 surface about 1/2 inch thick. In a smaller pan this cake rises too high and sinks in the middle.

Ingredients for a 9×13 Pistachio Cake

Cake

1 box (about 15 ounces) white cake mix
1 box (3.4 ounces) instant pistachio pudding mix
3 large eggs
3/4 cup vegetable oil
1 cup club soda or water
1/2 teaspoon almond extract (optional)
1/2 cup shelled pistachios, finely chopped

Pistachio Pudding Frosting

1 box (3.4 ounces) instant pistachio pudding mix
1 cup cold whole milk
8 ounces frozen whipped topping, thawed (or 2 cups heavy cream whipped to stiff peaks with 1/4 cup powdered sugar)
1/4 cup shelled pistachios, chopped, for the top

How to Make Pistachio Cake in a 9×13 Pan

Heat the oven to 350°F and grease and flour a 9×13 pan.
Mix the batter. Beat the cake mix, pudding mix, eggs, oil, club soda and almond extract on medium speed for 2 minutes. Fold in the chopped pistachios.

Bake 35 to 40 minutes, until the top springs back and a toothpick in the center comes out clean.
Cool completely in the pan, at least 1 1/2 hours. Frosting a warm cake melts the whipped topping.
Make the frosting. Whisk the pudding mix with the cold milk for 2 minutes until thick, then fold in the whipped topping.

Frost and chill. Spread the frosting over the cake, scatter the chopped pistachios and refrigerate at least 1 hour before cutting.

Cook and Prep Times

Prep: 15 minutes
Bake: 35 to 40 minutes at 350°F
Cool and chill: 2 1/2 hours
Serves: 15 to 18 squares

Changing the Pan Size

Bundt pan: use the full batter and bake 45 to 50 minutes; skip the pudding frosting and use a simple powdered sugar glaze instead.
Two 8×8 pans: divide the batter and bake 25 to 30 minutes.

Cupcakes: fill liners two-thirds full and bake 18 to 22 minutes; makes about two dozen.

Storage

The frosting contains milk and whipped topping, so keep the cake covered in the refrigerator and eat it within 4 days. It is best served cold. Freezing is not recommended once frosted, because the pudding frosting weeps when it thaws.

Frequently Asked Questions

Why use club soda?

The bubbles lighten a heavy, pudding-enriched batter. Plain water works; the cake is just slightly denser.

Can I make it without a cake mix?

Yes, use a scratch white cake batter sized for a 9×13 pan and whisk the dry pudding mix into the flour. Add 2 extra tablespoons of milk, since the pudding absorbs liquid.

Does it taste strongly of pistachio?

Instant pistachio pudding tastes more of almond and vanilla than of the nut itself, which is why the chopped pistachios matter. The almond extract rounds out the flavor.

For more bakes sized for the same pan, see our eclair cake in a 9×13 pan, lemon lush in a 9×13 pan and coconut cake in a 9×13 pan.

Pistachio Cake in a 9×13 Pan