Purple Sweet Potato Croissants

Happy Thursday! We just got into SF late last night and you better believe our first stop this morning is gonna be Tartine Bakery for, yes, you guessed it, a healthy dose (can you say that if it isn't actually healthy) of their famous flakey creations!! After that I'm meeting up with Sarah (Snixy Kitchen) and Alanna (The Bojon Gourmet) at Craftsman and Wolves and I can't freakin' wait to hang with those awesome ladies as well as, well, eat more pastries!! Not a bad way to start a long weekend in one of my favorite cities ever! That being said, I'm regretting leaving my running shoes at home. Thank goodness for those SF hills; hope my boots are up for the challenge. 

Let's just go ahead right now and call this the Viennoiserie week because 1) Shoyu Sugar Spam and Kimchi Musubi Croissants 2) Tartine 3) Craftsman and Wolves 4) Mr. Holmes Bakehouse 5) Neighbor Bakehouse 6) b. Patisserie 7) THESE PURPLE SWEET POTATO CROISSANTS. Don't say butter overload. Just don't. And please don't say carbs on carbs on carbs on carbs on BUTTER. Cause I forgot my running shoes. Maybe a trip to Niketown is in order... :D :D :D.

Enough about my Viennoiserie week, let's focus on these purple sweet potato croissants I'm sharing with you today. After Tuesday's sweet, salty, meaty "robust" croissants, I felt like I had to make something sweet and almost (ok not really) healthy to balance out the pastry scale. Luckily for me, my dear friend Valerie, who recently moved down to LA (hip hip hooray), was over enjoying some spam croissants, and I was able to pick her amazingly creative brain. Girlfriend is the best for dreaming up magical recipes with, because I swear she dreams in a million colors and seems to be a walking ingredient encyclopedia. After a bit of back and forth, she suggested trying something with ube. Guys, I love ube, do you? If you aren't familiar with it, it's a purple yam and pretty amaze. It's used in a bunch of different desserts, like ice cream, cookies, tarts, Swiss rolls, cakes, and can even be made into a sweet jam called ube halayá (hello halo-halo!). And it's always confused with Okinawan purple sweet potatoes!

So, let me be super duper honest and admit right now that I had my heart set on making some coconut-ube croissants but couldn't find ube ANYWHERE. I'm talking I hit up five stores and most of the employees looked at me like I was crazy when I asked them for purple yam, "you know, ube?". Ya, no. They don't know. But I did find purple sweet potatoes so all was not lost. This purple sweet potato filling is a cinch to whip up. It takes less than ten minutes to boil the potatoes and then after another ten minutes of cooling, all you do is peel, cube, and purée said potatoes with coconut milk and a bit of sugar and boom. Purple sweet potato paste, which you can totally add a bit of condensed milk to, and cook down to make the sweet potato version of ube halayá if you want! I myself just went ahead and spread it onto some buttered toast and called it a day. You can also turn it into vibrant 'purpley'-magenta ice cream (don't be surprised if you see that sooner than later here btw :D). Endless opportunities here, you guys. And before I ramble on any longer, I'm gonna go ahead and say this is the perfect way to end the blog's Viennoiserie week and ideal way to kick ofF my own personal Viennoiserie week here in SF. Again, SF recs are totally welcome and immensely appreciated. Also, if you're at the Cuesa Farmers Market at the Ferry Building this Saturday, please, please, holler!

Purple Sweet Potato Croissants

Croissant dough from Thomas Keller & Sebastian Rouxel's BOUCHON BAKERY

Idea dreamed up with Valerie

Makes 8 Croissants



  • 1  12"x9" sheet croissant dough from this recipe


  • 1/2 lb. purple sweet potatoes (around 2 potatoes)
  • 2 Tbsp. + 2 tsp. coconut milk
  • 1 Tbsp. granulated sugar
  • 1 Tbsp. + 1 tsp. melted unsalted butter



  • 1 large egg, beaten with fork then strained through a fine mesh strainer



  • Blender or food processor
  • Saucepan
  • Glass measuring cup
  • Measuring cups & spoons
  • Mixing bowls
  • Rolling pin
  • Ruler
  • Baking sheets lined with parchment or silpat mats
  • Sharp knife or pastry wheel (w/straight blade)
  • Pastry brush
  • Plastic tubs or cardboard boxes
  • Wire rack
  • Spoon



  1. See this recipe.


  1. Boil the sweet potatoes in a saucepan (large enough to fit potatoes) until fork tender (around 8-10 minutes). Let them cool (until they can be easily handled) then peel and cut into small cubes. Should yield around 3 cups of cubed sweet potatoes.

  2. Combine sweet potatoes, coconut milk, granulated sugar and melted butter and pulse/blend in a food processor/blender until smooth. Set aside to cool completely.


  1. Spray two sheet pans with nonstick spray and line with parchment paper (or just use 1 sheet pan if only using half the batch of dough).
  2. Lightly flour the work surface.  Remove one piece of dough from the freezer and position it on the work surface with the short end towards you. Roll the dough out to a rectangle 19 x 9 inches.
  3. Turn the dough so that a long side is facing you and trim it to 18 inches long.  Trim the remaining sides only as needed for straight edges.
  4. Cut the dough in half, crosswise, so that you have two squares, about 9 x 9 inches wide.  Then cut each squash in half so that you end up with four rectangles.  Cut each rectangle diagonally so that you end up with 8 right triangles. (Somehow I skipped cutting them into squares so I magically produced 9 instead of 8.)
  5. Hold one triangle up by the base with one hand and, using your fingertips, gently pull the dough until it is stretched to about 12 inches.
  6. Replace the dough on the work surface, with the base of the triangle close to you.  Place one tablespoon of potato purée at the base of the triangle. Fold over the corners to the center of the base and roll the dough up from the wide end to the tip. (see above gif) Put on a prepared sheet with the tail tucked under.  Repeat with the remaining 7 triangles of dough, spacing them evenly on the sheet pan.
  7. Brush the croissant tops and sides with beaten egg wash. Cover the pans with plastic tubs or cardboard boxes and let proof for about 2 to 3 hours. When the dough is delicately pressed with a finger, the impression should remain.
  8. Position the racks in the upper and lower two-thirds of the oven.  Preheat to 350°F.
  9. Bake for 25 minutes then quickly brush with beaten egg wash and sprinkle with shredded coconut or coconut chips (or both). Be sure to separate any croissants that are touching and rotate the pans before quickly replacing in oven. Bake for an additional 10-15 minutes or until the tops are a rich golden brown and no portions, particularly between the layers, look undercooked. Set the pans on a rack and cool completely.
  10. Serve and enjoy!