caramelized white chocolate buttercream PUMPKIN BARS

here’s a fact about me- im not super into pumpkin. pumpkin spice, yes. chai spice, yes. give me all the warm cozy spices. but, pumpkin just doesn’t do much for me. that is, until now. this recipe takes everything i love about fall desserts and puts it into the ultimate fall treat. these caramelized white chocolate buttercream pumpkin bars are it. the best pumpkin dessert ive ever had.

ok, what makes THIS recipe special?

oh, that would be the LAYERS and layers of flavor. but, seriously, they work so well together! here are the highlights:

im literally drooling while typing this. seriously. its not often i go back for thirds, fourths, ok….. half the sheet pan’s worth before “deciding” the recipe was perfect. grab my tips tips to make the perfect caramelized white chocolate, here.

caramelized white chocolate buttercream pumpkin bars

pumpkin pairs well with

ok, for all you pumpkin lovers out there, you probably already know this! but, for the non pumpkin obsessed among us (hey!!), pumpkin pairs well with SO MANY things. here are just a few:

  • cayenne, chilies + pepper
  • allspice, cinnamon, cloves, ginger, nutmeg + vanilla
  • browned butter, butter, cream, cream cheese, mascarpone, milk + whipped cream
  • almonds, hazelnuts, pecans + walnuts

in case you’re interested, these caramelized white chocolate buttercream pumpkin bars have “a few” of those perfect pairings! aka, they’re going to be delicious!

some of my favorite ingredients to make this

this is a simple cake, so quality ingredients make a big difference! here are some of my personal pantry favorites.

caramelized white chocolate buttercream pumpkin bars
caramelized white chocolate buttercream pumpkin bars
caramelized white chocolate buttercream pumpkin bars
caramelized white chocolate buttercream pumpkin bars

more fall dessert inspiration

caramelized white chocolate buttercream pumpkin bars

Megan
moist and fluffy brown butter pumpkin bars topped with creamy caramelized white chocolate buttercream. the ultimate fall dessert!
0 from 0 votes
Prep Time 1 hr 20 mins
Cook Time 35 mins
Cooling Time 35 mins
Total Time 2 hrs 30 mins
Course Celebrations, Dessert
Cuisine American
Servings 24

Equipment

  • stand mixer with paddle attachment
  • 9X13 baking pan
  • parchment paper
  • baking sheet

Ingredients
  

brown butter pumpkin bars

  • 2 c all purpose flour (240g)
  • 1 tsp baking soda
  • 1 tsp baking powder
  • 1 tbsp pumpkin pie spice (see notes)
  • 1/2 tsp salt
  • 1 c unsalted butter (227g), browned and cooled to room temperature (170g) (see notes)
  • 1 c packed light brown sugar (220g)
  • 1/4 c sugar (50g)
  • 3 large eggs, room temperature
  • 1 c pumpkin puree

caramelized white chocolate mascarpone buttercream + toasted walnuts

  • 6 oz. caramelized white chooclate (150g) (see notes)
  • 1 c unsalted butter, softened (113g)
  • 8 oz. mascarpone cheese, room temperature
  • 2 1/2 c powedered sugar, sifted
  • 1 tsp vanilla bean paste (alt. use vanilla extract)
  • 1/2 tsp salt
  • 1/3-1/2 c crushed walnuts, lightly toasted

Instructions
 

brown butter pumpkin bars

  • To make the brown butter, melt butter in a clear heavy bottom pot. Once the butter starts to foam, whisk continuously until brown bits start to form. Remove from heat, pour into clean bowl, skim the foam from the top and cool to room temperature (30 minutes).
  • Line 9×13 baking pan with parchment paper and preheat oven to 350F. Whisk together flour, baking powder, baking soda, salt and pumpkin spice. Set aside.
  • In a stand mixer with paddle attachment, browned butter, and sugar until smooth and well combined. Add eggs, beating well after each one until well combined. Add pumpkin puree and vanilla bean paste, beating until well combined.
  • Add dry ingredients to the wet 1/2 batch at a time. Slowly beat each time until JUST combined. A few flour streaks is okay! Drop evenly sized scoops into the prepared pan. Evenly press batter/dough into the pan.
  • Bake at 350 for 35-45 minutes or until a toothpick inserted into the center comes out clean or with a few moist crumbs. Pull from the oven, and allow to cool min. 60 minutes. Pumpkin bars should be completely cool before frosting.

caramelized white chocolate mascarpone buttercream

  • Return caramelized white chocolate to liquid form by placing in a microwave safe bowl and heating in 20 second intervals (stirring after each) until melted. Cool to room temperature.
  • In a stand mixer, with paddle attachment, beat butter until light and fluffy, about 4-5 minutes. On the lowest speed, beat in the mascarpone cheese with butter until well combined. Go slowly or you risk the cheese breaking. Once combined, slowly beat in cool (but still liquid) caramelized white chocolate. Add powdered sugar, a generous tablespoon at a time, beating slowly to combine. After adding about half the powdered sugar, add in the salt and vanilla bean paste. Beat until well combined. Add the remaining half of the sugar, a generous tablespoon at a time, beating until well combined. Once all the sugar is added, beat frosting on med-high until smooth. Using a palette knife or spatula, spread frosting on top of cooled pumpkin bars.
  • To toast walnuts, line walnuts on a parchment lined baking sheet. Bake in oven at 350F for 8-10 minutes. Cool and roughly chop. Scatter on top of frosting.

Notes

pumpkin pie spice: Feel free to use a store bought version if you have one you like. If you’d like to make a homemade version, here is my preferred version: 
1/3 c ground cinnamon (32 g)
2 1/2 tbsp ground ginger (15 g)
2 tsp ground nutmeg (4g)
1 tsp ground allspice (4g)
1/2 tsp ground cardamon (1g)
Mix all ingredients together in a small mixing bowl. Store in an airtight container such as spice jar or small glass mason jar. 
browned butter: water evaporates from the butter while it is browning, accounting for the change in weight. If using melted butter, aim for 3/4 c or about 170g.
caramelized white chocolate: its preferred to use homemade for this, as you can adjust the level of caramelization to your tastes, however, it does require some advanced planning and about an hour of prep time. Worth it in my opinion. You can also use store bought, “golden” white chocolate which is basically the same thing. 
Keyword caramelized white chocolate, celebration, mascarpone, sheet cake, spiced
did you make this recipe?tag @olivesnthyme on Instagram

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3 thoughts on “caramelized white chocolate buttercream PUMPKIN BARS

    1. Hi Jasmine! Sorry for the confusion. It should read 1 c unsalted butter, softened (226g). If you have any other questions please let me know!

  1. Hi Megan, thanks for such a quick response! Am excited to try this receipe out for my mothers birthday cake this saturday! Have tried your receipe for tahini brownies and it was sooo good! 🙂 thanks again!

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