Cranberry Crumble Bars with Oat Crust

Cranberry Crumble Bars

These thick cranberry crumble bars have a tart, jammy cranberry-orange center between a firm oat crust and a chunky golden topping. The same buttery oat mixture makes both the base and the crumble.

Cooking the cranberries until thick keeps the filling from soaking into the crust, while a short par-bake gives the base extra structure. Cool the baked slab completely, then chill it before cutting so the red fruit layer stays in place.

Ingredients for Cranberry Crumble Bars

Cranberry filling

• 12 ounces fresh or frozen cranberries (340g)
• 1/2 cup granulated sugar (100g)
• 1 tablespoon orange zest
• 1/3 cup fresh orange juice (80g)
• 1 tablespoon cornstarch (8g)
• Pinch of fine salt, from the amount listed below

Oat crust and crumble

• 1 1/2 cups all-purpose flour (180g)
• 1 1/2 cups old-fashioned rolled oats (135g)
• 1/2 cup packed light brown sugar (105g)
• 1/4 cup granulated sugar (50g)
• 1 teaspoon ground cinnamon
• 1/2 teaspoon fine salt, divided
• 3/4 cup unsalted butter, melted and slightly cooled (170g)
• 1 teaspoon vanilla extract

Optional finish: 1 to 2 teaspoons confectioners’ sugar, for dusting before serving.

How to Bake Cranberry Crumble Bars

1. Prepare the pan: Position a rack in the center of the oven and preheat to 350°F (175°C). Line a 9-inch square metal baking pan with parchment, leaving overhang on two opposite sides for lifting out the bars.
2. Cook the filling: Combine the cranberries, 1/2 cup granulated sugar, orange zest, orange juice, cornstarch, and a pinch of salt in a medium saucepan. Cook over medium heat for 10 to 15 minutes, partially covered while the berries pop and stirring frequently. Uncover as they soften; reduce the heat to medium-low if the mixture bubbles aggressively. The filling is ready when most berries have burst and it is glossy and thick enough to mound on a spoon. A spatula should leave a brief trail across the bottom of the pan. Keep it spreadable rather than cooking it dry.
3. Mix the oat crumble: In a large bowl, stir together the flour, oats, brown sugar, remaining 1/4 cup granulated sugar, cinnamon, and remaining salt. Add the melted butter and vanilla. Mix just until the crumbs are evenly moistened and hold together when squeezed, with irregular clumps still visible.
4. Par-bake the crust: Set aside about 1 1/2 cups of the oat mixture for the topping. Press the rest firmly and evenly into the prepared pan, including the corners. Bake for 10 minutes, until the edges begin to look dry.
5. Assemble the bars: Spread the thick cranberry filling evenly over the warm crust. Scatter the reserved oat mixture over it in loose clusters; do not press the topping down.
6. Finish baking: Bake uncovered for 25 to 30 minutes, checking at 25 minutes. The crumble should be golden and dry-looking on its high points, with filling bubbling around some edges. If the topping turns golden before the filling bubbles, loosely tent the pan with foil for the final minutes.
7. Cool and cut: Cool completely in the pan on a wire rack, about 1 1/2 to 2 hours, then refrigerate for at least 1 hour. Lift out the cold slab using the parchment and cut into 16 squares with a sharp knife, wiping the blade between cuts. Dust lightly with confectioners’ sugar, if using, just before serving.

Why the Filling and Pan Size Matter

The cranberry filling needs to be thick before it goes onto the crust: excess liquid can soften the base and leave the fruit layer loose at the cut edge. The 10-minute par-bake helps the pressed oats stay distinct beneath the filling.

Use a 9-inch square pan for thick bars. A different pan size changes their thickness and baking time. Even when the topping looks fully baked, warm filling can ooze during cutting, so allow time for both cooling and chilling.

Fresh, Frozen, or Prepared Cranberries

Fresh and frozen cranberries work by equal weight. Add frozen berries without thawing; they may need a few extra minutes to burst and cook down.

For a shortcut, replace all the cranberry filling ingredients with about 1 1/2 cups thick, spreadable whole-berry cranberry sauce or cranberry jam. Skip the filling-cooking step. Reduce or drain loose sauce first; firm jellied sauce will not give the same berry-textured layer.

Storage and Make-Ahead

Store fully cooled bars in an airtight container in the refrigerator for up to 5 days, with parchment between layers. They can also sit covered at cool room temperature for up to 2 days. For neat slices, bake the bars a day ahead and chill them overnight before cutting.

Let refrigerated bars stand at room temperature for 20 to 30 minutes if you prefer a softer texture. To serve a bar warm, microwave it for about 10 to 15 seconds; the crumble will soften slightly.

To freeze, arrange cooled, cut bars in a single layer until firm. Transfer to an airtight container with parchment between layers and freeze for up to 3 months. Thaw overnight in the refrigerator or for about 1 hour at room temperature, then add any confectioners’ sugar.

For another cranberry-orange bake, try these Cranberry Orange Shortbread Cookies.

Nutrition

Approximate nutrition per bar, based on 16 bars without the optional confectioners’ sugar: 230 calories, 3g protein, 9g fat, and 34g carbohydrates. Per 100g of finished bars: approximately 330 calories, 4g protein, 14g fat, and 50g carbohydrates. Values vary with bar size and moisture lost during cooking and baking.