Dear Nigella Team, I understand from previous ASKs that I could use all butter for the Custard Cream Hearts recipe despite the firmer texture that it would produce.
However, out of curiosity, would it be a slightly better idea to replace the vegetable shortening with margarine or an olive spread (i.e. 50 grams unsalted butter + 50 grams margarine/olive spread)? Thanks a lot!
Nigella's Custard Cream Hearts (from FEAST) are shortbread-style biscuits that are sandwiched with a vanilla buttercream. The biscuit dough includes, if possible, vegetable shortening as this gives the biscuit a tender, melting texture. Butter can be used as an alternative but will give a slightly harder texture, though a more buttery flavour.
Whilst it is possible to use margarine (or an olive oil based spread) as an alternative, our preference is to use butter as the alternative. Hard margarine contains 16-20% water and the water content can be higher than this for some olive oil spreads. The water toughens the glutens in the flour, making the biscuits firmer when baked. Shortening does not contain any additional water, which is why it gives the biscuits a more crumbly texture. Margarine also has less flavour than butter, so our preference would be to make the biscuits either with a combination of butter and shortening (for texture) or all butter (for flavour).