Step 1

Preheat oven to 170 degrees celsius (160 degrees if fan forced).

Step 2

Grease and line a 17X28cm slice tray with baking paper, allowing the edges to overhang.

Step 3

In a large bowl, whisk together the plain flour, rolled oats, salt, bi-carb soda, raw sugar and brown sugar.

Step 4

Add the melted butter and vanilla extract and stir mixture until well combined.

Step 5

Spoon half of the crumble mixture into the bottom of the prepared tin and press very firmly into an even layer. Bake in preheated oven for 15 minutes.

Step 6

Remove from oven and set aside (leave the oven turned on).

Step 7

To make the apple filling, place the sliced apples into a mixing bowl. Add the plain flour, raw sugar, cinnamon and nutmeg and mix until the apples are well coated.

Step 8

Spread the apple slices in an even layer over the top of the cooked base.

Step 9

Sprinkle the remaining crumble mixture over the top of the apple and press down lightly.

Step 10

Bake in oven for 25 minutes or until lightly golden.

Step 11

Remove from oven and allow to cool.

Step 12

Cover and refrigerate for at least 2 hours (preferably overnight) then take it out and cut into squares.

Step 13

Store in airtight container in refrigerator for up to 4 days.

Step 14

Preheat oven to 170 degrees celsius (160 degrees if fan forced). Grease and line a 17X28cm slice tray with baking paper, allowing the edges to overhang.

Step 15

Melt the butter and vanilla in the Thermomix bowl for 3 minutes, Speed 2, 50 degrees.

Step 16

Add the plain flour, rolled oats, salt, bi-carb soda, brown sugar and raw sugar. Mix for 20 seconds on Reverse, Speed Scrape down the sides. Mix for a further 20 seconds on Reverse, Speed 2.

Step 17

Spoon half of the crumble mixture into the bottom of the prepared tin and press very firmly into an even layer. Bake in preheated oven for 15 minutes.

Step 18

Remove from oven and set aside (leave the oven turned on).

Step 19

To make the apple filling, place the sliced apples into the Thermomix bowl. Add the plain flour, raw sugar, cinnamon and nutmeg and mix on Reverse, Speed 2 until coated (use the spatula to help mix).

Step 20

Spread the apple slices in an even layer over the top of the cooked base.

Step 21

Sprinkle the remaining crumble mixture over the top of the apple and press down lightly.

Step 22

Bake in oven for 25 minutes or until lightly golden.

Step 23

Remove from oven and allow to cool.

Step 24

Cover and refrigerate for at least 2 hours (preferably overnight) then take it out and cut into squares.

Step 25

Store in airtight container in refrigerator for up to 4 days or freeze for up to 3 months.