
I made this tart for a work potluck, and it was a huge hit. The oranges are roasted for so long that they are most of the way to marmalade by the time you’re eating it, which makes it a hit with me. There’s something about January/February that makes me crave marmalade. Probably because my mum cans 30+ jars of Seville orange marmalade every year to keep my dad in sandwiches for another 365 days. I’ll post about making my own marmalade later, today is about the tart.
I saw a basket of blood oranges at Safeway, and had to buy some most of them. I couldn’t remember seeing them there before, so they were a novelty. Then that night, I was reading my February issue of Martha Stewart Living (on the iPad… Canada Post seems to have taken my Feb issue hostage) and found this tart recipe. I figured it was a sign, and arranged a potluck at work for the next weekend so I’d have an excuse to make it.

Roasting the oranges was fun, and made the kitchen smell delicious. I started with those, as they roast for 2+ hours, and made the tart shell in between basting the oranges with orange juice. I feel like that shortened some of the kitchen time, as you have to be in and out of the oven every 30 minutes anyway.
Roasted Blood Orange Chocolate Tart – Adapted from (my hero) Martha Stewart’s Feb 2012 Living magazine.
I’ve laid out this recipe in the order I did things – give it a read through before starting to make sure it makes sense to you.
Makes 8 slices of tart.

Oranges, pre- and post- roasting. Inset is a regular orange for comparison.
Ingredients – for the roasted blood oranges:
4 blood oranges
1 1/4 cups fresh orange juice (4-5 regular oranges, squeezed)
1/3 granulated sugar
2 tablespoons water
Preheat oven to 325F. Leaving the peel on, cut oranges into 1/4″ rounds (I discarded the tops and bottoms that were all peel) and arrange them in a single layer on a rimmed baking sheet or large metal baking pan. Pour 1/4 cup of juice over the oranges. Lay a piece of parchment paper on top, then cover tightly with tinfoil. Cook until peel is tender, about 2 hours, pouring 1/4 cup of juice over them every 30 minutes.
Ingredients – for the tart shell:
1 cup all purpose flour
1/3 cup unsweetened cocoa powder
3/4 teaspoon salt
1/2 cup unsalted butter, room temperature
1 large egg yolk
3/4 teaspoon pure vanilla extract
3 tablespoons heavy cream
Once the tray of oranges is in the oven, mix together the flour, cocoa powder, and salt in a medium bowl. Beat the butter and granulated sugar on medium speed in a mixer fitted with the paddle attachment until pale and fluffy, about 3 minutes. Beat in egg yolk and vanilla to combine. Reduce the speed to low, and add flour mixture in 3 additions, alternating with the cream in 2 additions (I did 2 tablespoons for the first cream installment, and 1 for the second). Shape the dough into a disk and refrigerate until oranges are at 1.5 hours in the oven.
Ingredients – for the filling:
1 cup/250mL mascarpone cheese (at room temperature or close to it, so it is easily mixable)
2 teaspoons powdered sugar
1 orange
Once the dough is in the fridge, zest the orange, then mix the zest and powdered sugar into the mascarpone. Refrigerate if you are assembling the tart on another day, leave out to stay soft if you are doing it today.
At the 1.5-hour mark for the oranges, take your tart dough out of the fridge. Roll it out to a little less than 1/4″ thickness on a lightly floured surface. Fit the dough into a 9″ fluted tart pan with removable bottom. (I found mine at Crate & Barrel) If it tears a little, just patch it with scraps, pressing and smoothing the edges down so everything is level. Trim the edge flush with the top of the pan. Chill in the freezer for 15 minutes.
At the 2-hour mark for the oranges, increase the oven temperature to 375F. Remove and discard the tinfoil and parchment paper, then sprinkle oranges with the granulated sugar. Add the last 1/4 cup of orange juice, then return oranges to the oven for 15 minutes. Add the water and roast until slightly golden, 2 – 3 minutes more. Cool completely. I pulled my oranges out of the pan and let them cool on wax paper, because I was pretty sure that when they (and all the sugar/juice in the pan) had cooled, they’d be cemented to the cookie sheet.
Reduce oven temperature to 350F. Take tart shell out of the freezer and prick the bottom all over with a fork. Bake until firm, about 20 minutes. Let cool completely in the pan on a wire rack.
Assemble the tart by spreading the mascarpone in the shell, then layering roasted oranges on top.

Storage:
Completed tart can be stored at room temperature for up to one day (I used a cookie tin that probably doesn’t seal completely).
Un-baked tart dough can stay in the fridge for up to 2 days.
I stored my roasted blood oranges overnight on the counter at room temperature in plastic containers with the lids not quite fully closed, so they didn’t get too soggy. The tart shell I left out, uncovered. Mascarpone should go in the fridge overnight, but remember to let it warm up before trying to spread it.
