Apple Crumble Slice Bars

Buttery oat crumble bars filled with soft cinnamon-spiced apples and finished with golden walnuts.

by Samantha Tulett

Published May 18, 2026

RECIPE ↓

50 MINS + COOL

EASY

MAKES 9

About the Recipe

These Apple Crumble Slice Bars are everything I love about apple crumble, baked into neat little bars you can slice, share and keep sneaking from the tin. They have a buttery oat crumble base, a soft Pink Lady apple filling, a golden crumble topping and just enough walnuts for a little crunch.

I love this kind of bake because it feels cosy and nostalgic without being fussy. The apples are gently cooked first with brown sugar, lemon, cinnamon, ginger and vanilla, so the filling is already glossy and fragrant before it goes into the oven. Once baked and cooled, the bars hold together beautifully, making them perfect for afternoon tea, dessert, lunchboxes or a very efficient “just one more piece” situation.

RECIPE

Apple Crumble Slice Bars

by Samantha Tulett | City Slicker

25 MINS

PREP TIME

BAKE TIME

25 MINS

TOTAL TIME

50 MINS + COOL

INGREDIENTS

For the crumble base and topping

155 g plain flour

125 g brown sugar

55 g rolled oats

Generous ½ tsp fine sea salt

145 g unsalted butter, melted

For the apple filling

350 g Pink Lady apples, about 2 to 3 medium, cored and chopped

50 g brown sugar

Juice and zest of ½ lemon

1 tsp ground cinnamon

¼ tsp ground ginger

½ tsp vanilla extract

1 tsp cornflour

To finish

30 g walnuts, roughly chopped

METHOD

Preheat oven to 180°C fan-forced. Line a 20 x 20 cm square baking tin with baking paper, leaving a slight overhang for easy removal.

In a medium bowl, combine the flour, brown sugar, rolled oats and salt. Pour in the melted butter and mix with a spatula until the mixture forms a coarse, crumbly texture.

Reserve about ¾ cup of the crumble mixture for the topping, then press the remaining mixture firmly and evenly into the base of the prepared tin.

Place the chopped apples, brown sugar, lemon juice, lemon zest, cinnamon, ginger, vanilla and cornflour in a small saucepan over medium heat. Cook for 3 to 4 minutes, stirring occasionally, until the apples begin to soften and the mixture looks lightly glossy.

Spread the warm apple mixture evenly over the crumble base.

Scatter the reserved oat crumble over the apples. Sprinkle the chopped walnuts over the top. Lightly press the topping, but do not compact it. You want it to stay crumbly.

Bake for 25 to 30 minutes, or until the topping is golden and the apple filling is bubbling around the edges.

Allow the slice to cool completely in the tin for at least 1 hour, or until set. Use the baking paper overhang to lift it out, then cut into 8 bars.

Tips

Cool completely before slicing. This is the difference between neat bars and delicious apple rubble. The crumble base needs time to firm up, and the apple filling needs time to settle. Leave the slice in the tin for at least 1 hour before lifting it out and cutting.

Use Pink Lady apples. Pink Lady apples are sweet, slightly tart and hold their shape nicely when cooked. You want the filling to soften, but not collapse into apple sauce.

Reserve the topping before pressing the base. Once the crumble mixture is made, scoop out about ¾ cup for the top before pressing the rest into the tin. This keeps the base generous and firm while still giving you a golden crumble topping.

Do not compact the topping. The base should be firmly pressed, but the topping should stay loose and crumbly. Scatter it over the apples, then press very lightly so it catches in the filling without becoming dense.

For cleaner slices. Once cooled, use a sharp knife and wipe the blade between cuts. For extra neat bars, chill the slice briefly before cutting.