Step 1

Add the flour, sugar, and salt to a mixing bowl. Toss to combine.

Step 2

Rub in the cold butter until coarse crumbs form, using your fingers to work the butter into the dry ingredients. Pour in the cold water. Mix until a shaggy dough ball forms.

Step 3

Transfer the dough to a clean surface and shape it into a flat, 1” disk. Wrap with plastic wrap and chill for 1 hour.

Step 4

Preheat the oven to 425°F. Line a sheet pan with a piece of parchment paper.

Step 5

Combine the sliced plums with both sugars, the cornstarch, thyme sprigs, and a pinch of salt in a mixing bowl. Gently toss to combine. Let sit for 20 minutes until the sugars are dissolved.

Step 6

Remove the dough from the fridge and let it sit for about 5 minutes. Working on a well-floured surface, roll the dough into a 12-inch circle. Transfer the dough to the sheet pan.

Step 7

Use a slotted spoon to drain the plums and arrange them over the surface of the dough, leaving a 1-inch border. Fold and pinch the edges of dough over the plum filling. Brush the edges with the beaten egg and then sprinkle the raw sugar on top.

Step 8

Bake the galette for 20 minutes. Drizzle the syrup from the bowl of plums over the plums. Bake for another 10-15 minutes, or until the edges are golden and the plums are tender.

Step 9

Remove the sheet pan from the oven and transfer the galette to a cutting board. Let sit for a few minutes before slicing. Serve with a dollop of whipped mascarpone (instructions below) and a sprinkle of thyme leaves. You could also opt to serve with ice cream.

Step 10

Pour the heavy cream into a stainless steel mixing bowl. Whisk until frothy.

Step 11

Add the powdered sugar. Continue to whip until soft peaks form.

Step 12

Whisk in the mascarpone cheese until smooth. Mix in the almond extract.