Buttery Walnut Blondies
Rich, buttery squares with a crunchy walnut bite.
Allergens: contains cereals containing gluten, eggs, milk, tree nuts. Brands differ, so always check the labels on what you buy.
Per serving (approx.): 26g carbs · 17g sugars · 1g fibre. Estimates for carb counting, not medical advice. If you have diabetes, follow your GP or dietitian's advice.
Not every ingredient has a checked price at Asda, Aldi, Morrisons, Co-op, Iceland, so they aren't compared here yet (more are checked every day). Lidl doesn't publish prices online, so it can't be compared.
Ingredients and prices
Swipe the table to see every supermarket.
| Ingredient | Tesco | Sainsbury's |
|---|---|---|
| Unsalted butterpack 250g · use 125g | £1.85£0.74 per 100g | £1.85£0.74 per 100g |
| Caster sugarnot compared | – | £1.90 |
| Plain flouruse 150g | £0.801.5kg · £0.05 per 100g | £0.45500g · £0.09 per 100g |
| Eggspack 6 pack · use 2 | £1.80£0.30 each | £2.40£0.40 each |
| Walnutsuse 50g | £2.25200g · £1.13 per 100g | £1.90100g · £1.90 per 100g |
| Basket total (full packs) | £6.70 | £6.60 |
| Cost of what this recipe uses | £2.17 | £2.81 |
| Per serving | £0.18 | £0.23 |
Not compared (a price wasn't found at every shop, so it isn't in the totals): Caster sugar.
From your cupboard
Not in the prices above. Check you have these before you start.
Prices checked on 5 October 2026 from each supermarket's own listing or a price-comparison site. Each shop's unit price (or pack size) is shown under its price, and "cost of what this recipe uses" compares like with like (tap a price to see its source). Cheapest in each row is ticked. Prices, offers and pack sizes change; loyalty-card prices are not included unless stated.
Method
The method is written for 12. For a different number, use the amounts in the table above.
- Preheat the oven to 180C (160C fan, gas 4). Grease and line a 20cm square baking tin with baking parchment, leaving a little overhang for easy lifting. Roughly chop the 50g walnuts into small pieces, then set aside. Weigh out the 125g unsalted butter, 200g caster sugar, 150g plain flour and have the 2 eggs ready at room temperature.
- Place the 125g butter in a medium heatproof bowl and melt it in the microwave in 20-second bursts, or over a pan of barely simmering water, until completely liquid and hot but not boiling. Stir in the 200g caster sugar and a pinch of salt, mixing vigorously with a wooden spoon for 1 minute until the mixture looks glossy and the sugar has mostly dissolved. Let it cool for 3 minutes.
- Crack the 2 eggs into the warm butter-sugar mixture and beat thoroughly with a whisk or fork for 30 seconds until fully incorporated and the batter is smooth and shiny. Add 1 tsp vanilla extract if using, then sift in the 150g plain flour. Fold gently with a spatula until just combined — stop as soon as no streaks of flour remain; overmixing makes tough blondies.
- Fold the chopped 50g walnuts into the batter, distributing them evenly throughout. Scrape the thick batter into the prepared tin and smooth the top with the back of a spoon or an offset spatula, pushing it into the corners. The surface should look level and slightly sticky.
- Bake on the middle shelf for 22–25 minutes. The blondies are done when the edges are golden brown and pulling away slightly from the tin, the centre is set but still soft, and a skewer inserted 2cm from the edge comes out with a few moist crumbs but no wet batter. A slight wobble in the very centre is perfect.
- Remove the tin from the oven and place on a wire rack. Cool completely in the tin for at least 30 minutes — this finishing set is crucial for clean slices. Once cold, lift the blondie slab out using the parchment overhang and transfer to a board. Cut into 12 equal squares with a sharp knife, wiping the blade between cuts.
- Serve the buttery walnut blondies at room temperature. They taste rich, sweet and nutty with a dense, fudgy crumb. Store leftovers in an airtight tin at room temperature for up to 4 days, or freeze for longer keeping.
Tips
- Swap walnuts for cheaper pecans or omit entirely for a plain buttery blondie; add 50g white chocolate chips for extra sweetness if desired.
- Cool completely before cutting or they will crumble. Store in the fridge for up to 2 days — do not leave at room temperature as it dries them out.
- Freeze whole slab or individual squares wrapped tightly in cling film then foil for up to 3 months. Defrost in the fridge and eat within 24 hours; reheat only once, until steaming hot throughout.
Nothing wasted: your leftover ingredients
Supermarkets sell set pack sizes, so you'll have some ingredients left. Here's how to keep them, and other recipes here that use them up.
- Unsalted butter · about 125g left
Check the label: most raw ingredients can be frozen before their use-by date, and cupboard staples keep for months. Use it in: Banana muffins, Ginger Cake, Pad Thai with Chicken. - Caster sugar · about 800g left
Check the label: most raw ingredients can be frozen before their use-by date, and cupboard staples keep for months. Use it in: Banana muffins, Ginger Cake, Sticky Teriyaki Chicken Thighs. - Plain flour · about 1.35kg left
Dry stores keep for months sealed in the cupboard, so nothing goes to waste. Use it in: Banana muffins, Ginger Cake, Turkey Burgers with Sweet Potato Fries. - Walnuts · about 50g left
Check the label: most raw ingredients can be frozen before their use-by date, and cupboard staples keep for months. Use it in: Golden Syrup Flapjack Bars, Chocolate Rocky Road Slice, Cherry bakewell traybake.
Storing leftovers
Cool leftovers and put them in the fridge or freezer within 1–2 hours. Eat fridge leftovers within 2 days, or freeze them. Defrost in the fridge and reheat only once, until steaming hot all the way through (Food Standards Agency guidance).