One ingredient that seems to love Nutella is banana and the dish I've made takes advantage of this. I've used nutella and banana as the filling to a rich, buttery slice. I've also amplified the hazelnut aspect of nutella by adding ground hazelnuts to the base.
200 grams softened butter
160 grams pure icing sugar
150 grams ground hazelnuts
250 grams plain flour
Place the butter and icing sugar into a bowl and beat until thick and creamy. Add in the flour and ground hazelnuts and on a low speed, beat until just amalgamated.
Remove 300 grams of the mixture and set to one side.
Line a shallow 20x30cm (8x12 inch) tin with baking paper making sure it overlaps the side of the tin. Scatter the rest of the mixture into the tin and press down to form a smooth base.
Dot the base with nutella and smooth it out to roughly cover the base - then scatter over with diced banana - the quantity of these ingredients I'll leave to you, use as much or as little of each as you prefer.
Take the reserved mixture and crumble it evenly over the top.
Bake in a preheated 170°C oven until golden and cooked through - around 40 minutes.
Once cooked, remove from the oven and allow to cool slightly in the tin - don't try to remove it when it's too hot as the pastry is quite short and will crumble.
When it is cool enough, use the overlapping baking paper to help slide it from the tin - let it finish cooling on the baking paper on a wire rack.
When ready, cut into slices and serve.
If you don't like banana, then strawberries can be substituted.
More Nutella Day action can be found:
On Twitter - send your messages to @NutellaDay or use the hashtag #nutelladay
On Facebook - check out the Nutella Day Page
On Flickr - visit the Nutella Day Group