Add coffee to the bowl one third at a time stirring hard after each addition until all incorporated and smooth.
40 ml strong black coffee
Add cream and stir until incorporated.
90 ml double cream (heavy cream)
Place in the fridge for three hours and make the biscuits whilst you're waiting.
Use electric beaters to whip the ganache until peaks form. It's now ready for spreading.
Biscuits
Place all ingredients except the coffee into a food processor and pulse until mixture resembles breadcrumbs. Or rub butter into dry ingredients by hand.
100 g wholemeal spelt flour, 100 g plain flour (all purpose flour), 100 g golden caster sugar, 100 g unsalted butter
Add coffee and pulse again. Or if making by hand, stir in with a knife
3 tbsp strong black coffee
Bring mixture together with hands to form a ball.
Place in a plastic bag and leave for ½ hr or so in the fridge to firm up.
Roll the bough out to just under ¼ cm thickness.
Cut out heart shapes.
Re-roll off cuts and carry on cutting until all the pastry is used up and you have 40 biscuits.
Place on 2 baking trays lines with silicone mats or baking paper and bake for 10 minutes at 180℃ (350℉, Gas 4). Remove to a wire rack to cool.
Spread the ganache over half of the biscuits and sandwich the remaining biscuits on top, to make 20.
Notes
Please note: calories and other nutritional information are per serving. They're approximate and will depend on exact ingredients used.