I am such a huge fan of rhubarb. I do like strawberry rhubarb but in my opinion just straight rhubarb is better. I developed this roasted rhubarb crumble cookie recipe in hopes that you’d fall in love with rhubarb too, if you aren’t already a lover. Rhubarb has a distinct tart flavor that becomes delicious when sugar is added. It’s different and unusual but in the most delicious way. The roasted rhubarb crumble cookie is special, I haven’t eaten anything quite like it. I added a crumble topping to really make the cookie come alive, its almost like a pastry or muffin top but in cookie form- hints the name roasted rhubarb crumble cookie. 
Ingredients
- Rhubarb, cut and washed
- cornstarch
- unsalted butter
- granulated sugar
- light brown sugar
- large eggs
- salt
- pure vanilla extract
- all-purpose flour
- aluminum free baking powder
What to know about roasted rhubarb crumble cookies
- What does rhubarb taste like? Rhubarb is very tart which is why its cooked in sugar to counteract the sour flavor.
- When is rhubarb in season? Typically from April through June- The Pacific Northwest (where I live) gets a second harvest in June or July.
- How do I harvest rhubarb? Trim off the leaf of the rhubarb stalk and cut 1 inch off the bottom of the stalk from where it comes from the ground. That part is always a little tough so let’s cut it off. Harvest the long thick stalks that turn deep in color. About 1 inch and thicker. The lighter rhubarb is more porous and lacks in flavor, unless you have a green rhubarb plant that doesn’t turn pink.
- How do I roast rhubarb? Wash and dry rhubarb. Cut to 1 inch square pieces or cut at an angle for fancy looking rhubarb. It won’t matter what shape in the end because it will get mixed into the cookie dough.
- Why roast rhubarb?- Roasting rhubarb gives the rhubarb a deep and robust flavor that you won’t otherwise get by cooking on the stovetop.
- Why are my cookies flat?- Check the date on the baking powder, it expires and will not give you the lift you want. Creaming butter is important because it helps make the cookies rise.
- Can I use frozen rhubarb?- No, you can’t for this recipe. Rhubarb becomes soggy when de-thawed so roasting will turn it to complete mush.
- Which part of the rhubarb do I eat?- the stalk, not the leaves.
- Can I prepare the roasted rhubarb the day before?- Yes you can. Store in an airtight container in the fridge after completely cooled from roasting.
If you like Rhubarb
Try this Rhubarb Pie recipe 
Roasted rhubarb crumble cookies
Roasted rhubarb crumble cookies that are packed with butter and sweet roasted rhubarb for a delicious muffin top type cookie.
Ingredients
Roasted Rhubarb
- 3 cups rhubarb washed, dried and cut to 1 inch cubes
- 3/4 cup granulated sugar
- 1 tsp corn starch
Cookie
- 1 1/4 cup unsalted butter 2 1/4 sticks softened
- 1 tsp fine salt regular table salt
- 1 cup granulated sugar
- 1/2 cup light brown sugar lightly packed
- 1 tsp pure vanilla extract
- 2 large eggs cold
- 3 cups all-purpose flour spoon and level measured
- 1 Tbsp corn starch
- 1 Tbsp aluminum-free baking powder
crumble topping
- 3 Tbsp Salted butter
- 2 Tbsp granulated sugar
- 2 Tbsp firmly packed light brown sugar
- 1/3 cup all-purpose flour
Instructions
Roasted rhubarb
- Preheat oven to 425 degrees. on a cookie sheet, lay down parchment. Wash and dry rhubarb. Chop to 1 inch chunks. In a medium bowl, put chopped rhubarb, sugar and corn starch. Mix and set aside to macerate until the oven is preheated. Once the oven has reached 425, turn the rhubarb out on the cookie sheet with parchment in a single layer. Cook on the middle rack for 8 to 10 minutes. The rhubarb will be tender. Once it's done, place sheet in freezer or fridge to chill. Don't add hot rhubarb to the cookie dough.
- Turn off oven to wait for the rhubarb to chill, normally takes 15 to 20 minutes to cool off in freezer.
Crumb
- Use a food processor and add in the butter, flour and sugar. pulse until its combined and it looks crumbly. Set aside and make cookie dough.
Cookie
- Turn oven to 375
- In a stand mixer, cream butter, salt and both sugars together for three minutes on medium high speed to work air into the butter and dissolve the salt. Once that's creamed, add in vanilla and eggs, adding in one egg at a time and mixing in-between. Make sure to scrape down the sides with a rubber spatula so everything is incorporated.
- In a medium bowl, mix flour, corn starch and baking powder with a whisk and add it into the Ingredients mixed in the stand mixer. Once it becomes a dough, stop mixing.
- The rhubarb should be cooled enough from the freezer. Add it in gently by using a slotted spoon to reduce the juice going into the dough. The texture will be different if you add in juice- tap the slotted spoon against the bowl with each scoop, a little juice is fine. Use a folding motion to keep the rhubarb in tact and only mix a handful of times. There will be chunks of rhubarb in the dough so try not to smash it.
- Take an aluminum restaurant grade cookie sheet and line with parchment paper. Darker pans will brown on the bottom faster so keep that in mind. Use an ice cream scoop to measure each cookie. About 1/4 cup each. (you can make smaller cookies, decrease baking time) Place 6 large cookies per sheet.
- On top of each cookie, add some crumble.
- Bake on the middle rack, one sheet at a time. Bake for 12 to 14 minutes. Allow cookies too cool for a few minutes on the sheet and then transfer to cooling rack and cool completely or enjoy warm.