Would cocoa powder be a suitable substitute for chocolate Ovaltine in the Go Get 'Em Smoothie (Nigella Express, p86)? And just use less of it?
Do you recommend the "original" or "light" version of Horlicks for the Chocolate Brownie Bowls (Kitchen, p161)? For "original", you have to add milk, for "light", you have to add water. Hungryfrog.
Horlicks and Ovaltine are two brand names of malted milk powder and can be used interchangeably. We understand that Horlicks may contain slightly less sugar but as the quantities used in recipes are fairly small we do not believe it will make much difference when used in baking, it is added for the malt flavour. Nigella uses the "original" version (the type which you add milk to) in her recipes.
For the Go Get 'Em smoothie you could add cocoa instead of the chocolate Ovaltine if you do not have any Ovaltine, though the milkshake will be missing the malty flavour from the Ovaltine. As cocoa is unsweetened and slightly bitter, we would suggest adding one teaspoon first, then taste the milkshake and add more cocoa to taste, whizzing the milkshake in the blender between each addition of cocoa. You could also use a chocolate flavoured milkshake powder (such as Nesquick) or a regular hot chocolate powder (the type where you add milk) as alternatives. You are likely to need to use these in quantities closer to the Ovaltine but it is worth adding 2 teaspoons first and then adding more to taste.