This plum blackberry cobbler delivers the jammiest fruit filling with tender, crumbly hazelnut biscuit topping and satisfying crunch from chopped hazelnuts and demerara sugar.

Happy October! In a blink of an eye, all things fall have flooded the scene-apples, pears, figs, persimmons, pumpkins, squash, and Halloween decoration. I haven't quite made a complete switch to fall mode yet. When it comes to baking, I love the in between seasons, especially the period between summer and fall. While the peaches and nectarines have disappeared, the plums are still going strong. I got some beautiful plums from Sweet Tree Farms and threw them into a mouthwatering plum blackberry cobbler with hazelnut biscuit topping. Crumbles and cobblers are my go to rustic fruit desserts that can thrown together in a pinch to satisfy my pie craving without the fuss of messing with pie dough and crimping.

Ingredient Notes
- Plums: pick plums that feel heavy but not too soft. If the plum is too soft, it’s probably overripe. Unripe plums will soften a little in a brown paper bag at room temperature within a couple days but they won’t sweeten appreciably after they’re picked. Some of my favorite plums are Elephant Heart, Frontier, and Greengage. If you can't find plums, pluots make a great substitute.
- Blackberries: I like using fresh blackberries for the cobbler but frozen is fine. Make sure to thaw the blackberries completely first.
- Hazelnut: I like to grind my own hazelnut to control the texture of the hazelnut. Store bought ground hazelnut tends to be too fine and loses its texture.

Tips for Making Cobbler
- Slice the plums into bite-sized pieces for easier scooping and eating.
- Adjust the amount of sugar depending on whether your fruit is more sweet or tart. Blueberries, strawberries, peaches, nectarines, sweet cherries and pears usually need less sugar than more acidic blackberries, raspberries, sour cherries, plums, pluots, and apples.
- Tossing fruits with sugar and cornstarch before baking will create a lush sauce from the fruit’s juices.
- For the most tender biscuit topping, be sure to let the dough chill before baking.
- Use an ice cream scoop to remove the dough. Place the dough on top of the fruit filling leaving some space so the juice from the filling bubbles up around the dough. Completely covering the fruit filling with the cobbler topping will steam both the fruit and the bottom of the topping resulting in a overly wet and unappealing cobbler.
- Place the cobbler on a rimmed baking sheet to catch drips, or place aluminum foil beneath it in the oven.

How Long to Bake the Cobbler
Cobbler always takes a bit longer to bake than most people think. The fruit filling needs to come a full boil in the oven to ensure that the cornstarch is cooked enough for the sauce to properly thicken. Bake the cobbler for 40 minutes at 400 degrees F. A probe thermometer inserted in the center of the cobbler should reach about 200 degrees F in the thickest part of the topping. At 30 minutes if the biscuit topping starts to brown, take a piece of foil and cover the baking dish.

When the cobbler came out of the oven, the plums and blackberries developed a beautiful magenta color in contrast to the golden hazelnut biscuit topping. The cobbler delivered the jammiest plums and blackberries topped with a tender, crumbly biscuit topping and satisfying crunch from chopped hazelnuts and raw demerara sugar. It tasted even better than it looked. We enjoyed the cobbler still warm from the oven with generous scoops of vanilla ice cream. Desserts like this plum blackberry hazelnut cobbler is my ideal way of ending the night!

For more baking inspiration, check these recipes: apple rhubarb ginger crumble, peach and blueberry cobbler,


Plum Blackberry Cobbler with Hazelnut Biscuit Topping
Ingredients
Fruit Filling
- 1 pound plums, sliced into small pieces
- 8 ounces blackberries
- ¼ cup sugar
- 1 ½ tablespoons cornstarch
- scraped seeds from 1 vanilla bean
Biscuit Topping
- 1 cup all purpose flour
- ½ cup ground hazelnuts
- ¼ cup sugar
- ½ tablespoon baking powder
- 1 stick unsalted butter, cold and cubed
- ⅛ teaspoon salt
- ¾ cup heavy cream and extra for brushing
- 2 tablespoons demerara sugar
- 2 tablespoons chopped hazelnuts
Instructions
- In a food processor, pulse together flour, ground hazelnut, sugar, baking powder, and salt. Pulse in butter just until mixture looks like small pebbles. Drizzle in heavy cream, and pulse just to combine.
- Transfer dough to a lightly floured surface and pat dough together, incorporating any stray or dry pieces. Put dough into a large bowl and refrigerate for 30 minutes.
- In a large bowl, toss together plum slices, blackberries, sugar, cornstarch, and vanilla bean. Let sit for 30 minutes to macerate.
- Preheat oven to 400 degrees F.
- Transfer the fruit mixture to a large baking dish. It should fill the dish halfway to three-quarters full, leaving a good inch of space for the biscuit topping.
- Use a large ice cream scoop and scoop biscuit topping onto fruit filling leaving some spaces in between the biscuit.
- Brush biscuit topping with heavy cream. Sprinkle demerara sugar and chopped hazelnuts over the top.
- Place the cobbler on a rimmed baking sheet to catch drips, or place aluminum foil beneath it in the oven.
- Place baking sheet on middle rack and bake at 400 degrees F until the topping is turning golden brown around the edges and the fruit filling is bubbling.
- Remove cobbler from oven and let it cook for at least 15 minutes before serving.
Leave a Reply