Cozy up with these Williams Sonoma Pumpkin Bars - a gooey, spiced dessert made in one pan with cake mix and pumpkin butter, ready in 45 minutes.
Looking for the best pumpkin bars recipe that's easy, rich in fall flavor, and crowd-friendly? These copycat Williams Sonoma pumpkin bars are made with boxed cake mix and pumpkin butter for a gooey, spiced center and crisp topping.
UPDATED October 2025: Thoroughly tested and refined over the years; updated for improved clarity and storage tips. Inspired by the original Williams-Sonoma "Simple Fall Dessert Squares" and adapted for everyday home bakers. Retested using homemade pumpkin butter and adjusted crust method for easier spreading and better texture.
Why You'll Love This Recipe
- Easy to make with boxed cake mix - no special equipment required.
- Gooey center and crisp topping deliver perfect fall flavor in every bite.
- Great for potlucks, coffee dates, or Thanksgiving dessert trays.
✨Try it with our Homemade Pumpkin Butter or Pumpkin Spice Blend for extra flavor.
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A Quick Look At The Recipe
⏱ Prep Time: 10 minutes
🔥 Cook Time: 35 minutes
⏳ Total Time: 45 minutes
🍽 Servings: 16 squares
🌟 Skill Level: Beginner-Friendly
🦹 Key Ingredients: yellow cake mix, pumpkin butter, eggs, butter
I love baking a batch of these every fall and keeping them in the freezer - they're the perfect last-minute treat with coffee when friends drop by.
✨At Seanna's Kitchen, you'll find tested recipes and real-life cooking and baking tips-trusted by home cooks across the Midwest and beyond.
Here's What You Need (Ingredients)
- Pumpkin butter: Use store-bought or try our Homemade Pumpkin Butter for deeper spice and smooth texture.
- Yellow cake mix: Spice cake mix also works for a deeper fall flavor.
- Pumpkin spice: Try it with our Pumpkin Spice Blend.
See the recipe card for full information on ingredients and quantities.
Substitutions
- Gluten-free: Use a GF yellow cake mix and GF flour for the topping.
- Lower sugar: Cut topping sugar in half (2 tablespoons).
- Dairy-free: Substitute plant-based butter and milk.
- Pumpkin purée substitute: Mix canned puree with sugar and spices if pumpkin butter isn't available at Williams-Sonoma or Trader Joe's. See our Easy Pumpkin Butter Recipe.
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Variations and Add Ins
- Add chopped pecans or walnuts to the topping. Super tasty with Sweet & Spicy Pecans.
- Swirl in softened cream cheese into the filling layer for extra richness.
- Top with a dusting of powdered sugar or drizzle with caramel glaze. See our Apple Bundt Cake Recipe for an easy caramel glaze you can make.
- Bake in a 9x9 pan for taller, cakier squares (increase bake time ~5 min).
How to Make Williams Sonoma Pumpkin Bars
STEP 1: Preheat Oven.
Preheat oven to 350°F. Lightly grease a 9x13 baking pan or line with parchment.
STEP 2: Make the Base.
Reserve 1 cup of dry cake mix and set aside. In a bowl, mix remaining cake mix with 8 tablespoon melted butter and 1 egg. Press into bottom of pan.
STEP 3: Make the Filling.
Whisk together 16 oz pumpkin butter, 2 eggs, and 2 tablespoon milk until smooth. Pour evenly over crust.
STEP 4: Make the Topping.
Mix reserved cake mix with 1 tablespoon flour, 1 teaspoon cinnamon, and ¼ cup sugar. Cut in 4 tablespoon cold butter until crumbly. Sprinkle over filling.
STEP 5: Bake.
Bake for 35 minutes or until topping is golden brown and center is mostly set.
STEP 6: Cool & Slice.
Let cool completely before slicing into squares.
Recipe Tips
- Remove when center jiggles slightly: After testing this recipe many times, I've learned the bars are done when the center still jiggles slightly - they firm up as they cool.
- Keep the topping crumbly, not soggy: If your topping melts in, it's usually from overmixing or using butter that's too soft. Use cold butter and gently layer it over the filling.
- Make-ahead friendly: These bars freeze beautifully. I like to freeze them in single layers with parchment in between so I can grab just one or two.
- Serve chilled or room temp: They taste great either way, but slightly chilled bars slice cleaner and have a firmer bite - perfect with coffee or cider.
- Trick to the bottom layer: The bottom layer can be tricky to spread, so I avoid overmixing and drop it in clumps, then gently press them together. See the technique in the video inside the recipe card.
Serving Ideas
These dessert bars are delicious served warm or at room temperature with a dollop of whipped cream. Try pairing them with some hot apple cider, or coffee for a cozy fall treat, or include them alongside other Thanksgiving desserts on your holiday dessert tray. For a decadent twist, drizzle with caramel sauce and a pinch of sea salt.
Troubleshooting & FAQs
Yes! Wrap individual pumpkin bars in plastic wrap and freeze for up to 2 months. Thaw overnight in the refrigerator for best texture.
If you don't have pumpkin butter, you can use a mix of canned pumpkin, brown sugar, and pumpkin spice as a substitute for the filling in Williams Sonoma pumpkin bars.
Yes, you can substitute the yellow cake mix with a spice cake mix or vanilla cake mix in this Williams Sonoma pumpkin bars recipe. Spice cake adds extra fall flavor.
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📖 Recipe
Williams Sonoma Pumpkin Bars (Pumpkin Squares)
Equipment
Ingredients
- 1 box yellow cake mix set 1 cup aside
- 8 tablespoons butter melted
- 4 tablespoons butter cold, cut into pieces
- 3 eggs
- 16 ounces pumpkin butter
- 2 tablespoons milk
- 1 tablespoon all-purpose flour
- ¼ cup sugar (granulated)
- 1 teaspoon ground cinnamon
Instructions
Preheat oven to 350°F.
- Prepare Baking Pan. Lightly coat a 9x13 baking sheet with cooking spray.
- Make the crust: In a medium bowl, combine all but 1 cup of the cake mix with 8 tablespoons melted butter and 1 egg. Stir until crumbly. Drop clumps into the pan and press into an even bottom layer.1 box yellow cake mix, 8 tablespoons butter
- Prepare the filling: In another bowl, whisk together pumpkin butter, 2 eggs, and milk. Pour evenly over the crust.3 eggs, 16 ounces pumpkin butter, 2 tablespoons milk
- Make the topping: In a small bowl, mix reserved 1 cup cake mix, flour, sugar, and cinnamon. Cut in cold butter with a pastry cutter until the mixture forms coarse crumbs. Sprinkle evenly over the pumpkin layer.4 tablespoons butter, 1 tablespoon all-purpose flour, ¼ cup sugar (granulated), 1 teaspoon ground cinnamon
- Bake for 35 minutes, or until the center is just set and slightly jiggles when gently shaken.
- Serve. Cool completely before slicing into squares.
Video
Notes
- Don't overmix the bottom layer. The base should be soft and crumbly - mix just until combined, then drop in clumps and press gently into the pan for best texture.
- Bake until the center jiggles slightly. The pumpkin bars will continue to set as they cool, which keeps them moist and prevents overbaking.
- Cool completely before slicing. This helps the layers set and gives you cleaner, more defined squares.
- Pumpkin butter matters. Using pumpkin butter (not canned pumpkin) gives a smoother texture and deeper spice flavor. Try homemade or use store-bought.
- Freezer-friendly. These freeze beautifully - store in an airtight container for up to 2 months. Great for last-minute guests or a quick fall treat.
JoLynn says
Delicious! Do these need to be refrigerated?
Seanna says
Thanks JoLynn! No, they do not. Countertop is fine. I do love to freeze them, however. They're delicious cold, right out of the freezer.
Lynn says
Is 16 oz pumpkin butter by weight or 16 oz liquid measure? Thank you!
Seanna says
Hey Lynn, By weight. 16 Ounces of Pumpkin Butter plus or minus will work fine. This ingredient amount is pretty flexible. Now you've got me craving these!
Natalie says
That looks delicious. I'm going to give this a try.
Seanna says
Thanks Natalie. Hope you like it.
Jeri says
These pumpkin squares were so moist! Thanks for the recipe!
Seanna says
Thanks Jeri. So glad you think so!