Slow Cooker Toffee Crunch Blondies

Name: Slow Cooker Toffee Crunch Blondies
Prep time: 15 min
Cook time: 2 h 30 min
Total time: 2 h 45 min
Yield: 12 servings
Cuisine: American
Ingredients: 8 oz (227 g) unsalted butter, softened, at room temperature; 1¾ cups (350 g) packed light brown sugar; 2 large eggs, at room temperature; 1 tsp (5 ml) vanilla extract; 1½ cups (188 g) all-purpose flour; ¾ tsp (3¾ g) baking powder; ½ tsp (3 g) fine sea salt; 1½ cups (255 g) toffee bits; ¾ cup (128 g) semi-sweet chocolate chips (optional)

From the MyKitchenBank Kitchen

Fudgy, buttery blondies studded with toffee bits and baked in a slow cooker for a tender, chewy crumb. The gentle heat creates an extra-moist texture with crispy edges that rival oven-baked versions. Perfect for entertaining or when your oven is full.

Prep: 15 min
Cook: 2 hr 30 min
Wait: 30 min
Total: 3 hr 15 min
Makes: 12 blondies (one 9-inch square pan)

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Steps

Before you start

Line a 9-inch square (23 cm) baking pan with parchment paper, leaving overhang on two sides
Let butter soften to room temperature (about 30 minutes)
Have all ingredients measured and ready before you start
Plug in your slow cooker and line it with a silicone liners or foil if desired (not required but helpful for cleanup)

1
Cream butter and sugar
- In a large bowl or stand mixer, beat the softened butter and brown sugar together for 3–4 minutes on medium speed until pale, fluffy, and light in color.
- Scrape down the bowl halfway through.
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Ready when: mixture is pale, fluffy, and has increased in volume
Tip: Cold or room-temperature butter takes longer to cream; use softened butter for best results.
2
Add eggs and vanilla
- Add one egg at a time to the butter mixture, beating on medium speed for 30 seconds after each addition until fully incorporated.
- Add vanilla extract and beat for another 15 seconds.
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Ready when: batter is smooth and combined, no streaks of egg visible
Tip: Adding room-temperature eggs prevents lumping and ensures a smooth batter.
3
Combine dry ingredients
- In a separate small bowl, whisk together flour, baking powder, and salt.
- Set aside.
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Ready when: flour mixture is evenly combined with no lumps
4
Mix in dry ingredients
- Add the dry ingredient mixture to the wet ingredients and stir on low speed or by hand with a rubber spatula until just combined, about 30 seconds.
- Do not overmix.
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Ready when: no visible streaks of flour remain, batter is slightly thick and uniform
Tip: Overmixing develops gluten and makes blondies tough; stop as soon as streaks disappear.
5
Fold in toffee and chocolate
- Using a rubber spatula, gently fold the toffee bits and chocolate chips (if using) into the batter until evenly distributed, about 15–20 folds.
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Ready when: toffee and chocolate pieces are evenly scattered throughout the batter
Tip: Gentle folding prevents overmixing and keeps the crumb tender.
6
Prepare slow cooker
- Pour the batter into the parchment-lined 9-inch square baking pan, smoothing the top with a spatula.
- Place the pan on a trivet or crumpled foil in the base of your 6-quart slow cooker.
- (The trivet keeps the pan elevated and prevents direct heat from overcooking the bottom.)
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Ready when: batter is level in the pan, pan is secure on the trivet
Tip: Use a trivet or foil ball to create air circulation; direct contact with the slow cooker's heating element burns the bottom.
7
Slow cook the blondies
- Cover the slow cooker with its lid and cook on LOW for 2.5 hours (150 minutes).
- The blondies are done when a toothpick inserted in the center comes out with a few moist crumbs (not wet batter) and the edges have pulled slightly away from the pan sides.
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Ready when: toothpick inserted in center comes out with a few moist crumbs; edges have pulled slightly from pan
Tip: Slow cookers vary in heat intensity. Start checking at 2 hours 15 minutes. Overbaking by 10–15 minutes is better than underbaking.
8
Cool in slow cooker
- Turn off the slow cooker and leave the pan inside with the lid off for 15 minutes.
- This allows the residual heat to continue setting the blondies gently without overcooking them.
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Ready when: blondies are firm enough to handle, no longer steaming
9
Remove and cool completely
- Carefully lift the pan out of the slow cooker using oven mitts (it will still be hot).
- Set it on a wire rack and allow the blondies to cool to room temperature, about 1 hour.
- Using the parchment overhang, lift the block from the pan and place on a cutting board.
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Ready when: blondies are cool to the touch, no longer warm
Tip: Cooling completely before cutting prevents crumbling and makes cleaner, more attractive pieces.
10
Cut and serve
- Using a long serrated knife (dipped in hot water and wiped dry between cuts if needed), cut the blondie block into 12 equal squares (3 rows by 4 columns, each approximately 3 inches).
- Serve immediately or store.
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Ready when: 12 equal squares with clean, even cuts
Tip: Dipping the knife in hot water and wiping it between cuts prevents the batter from sticking and gives clean edges.

Good to know

Tips

Slow cookers have varying wattages and heating patterns. If your slow cooker runs hot, start checking at 2 hours 15 minutes. If it runs cool, you may need up to 2 hours 45 minutes. A toothpick test is your best friend here.
For extra-fudgy blondies, pull them out when the toothpick comes out with more moist crumbs; for a more cake-like texture, go longer until it comes out almost clean.
Line your baking pan with parchment paper overhang on two sides—it makes lifting the entire block out of the pan effortless and prevents sticking.
These blondies are best served slightly warm or at room temperature. If storing in the fridge, let them sit at room temperature for 15 minutes before eating to restore their tender crumb.

Make ahead

You can prepare the dry ingredients the day before in a sealed container. The batter itself should be mixed and cooked the day you serve the blondies, as it does not store unbaked."

Storage & reheating

Room temperature (covered): up to 3 days. Refrigerator (in an airtight container): up to 5 days. Freezer (wrapped individually in plastic wrap, then in a freezer bag): up to 3 months. Thaw at room temperature for 1 hour before serving, or reheat thawed blondies in a 300°F (149°C) oven for 5–8 minutes if you prefer them warm.

Substitutions

toffee bits → crushed heath or butterscotch chips, or a combination of both. Offers similar buttery, crunchy flavor and texture. Use the same quantity.
semi-sweet chocolate chips → chopped dark chocolate or milk chocolate, or white chocolate chips. Allows you to customize the flavor. Semi-sweet is classic, but dark chocolate adds richness and white chocolate adds sweetness.
packed light brown sugar → granulated sugar (use ¾ cup) plus 2 tablespoons molasses. Creates a similar depth of flavor if you don't have brown sugar on hand.
vanilla extract → 2–3 drops of almond extract, or omit for a less sweet variant. Almond extract adds a subtle nuttiness; omitting vanilla makes the toffee and chocolate shine.