Preheat the oven to 350°F (175°C). Grease a 12-tin muffin pan with butter and set aside.
In a medium bowl, whisk together the flour, powdered sugar, butter and salt until the mixture resembles coarse crumbs. Divide the mixture evenly among the muffin tins and press firmly into the bottom and up the sides. Bake for 15 minutes until lightly golden brown. Remove from the oven and let cool.
In a medium bowl, whisk together the cocoa powder, melted butter, light brown sugar, cinnamon and nutmeg. Gradually whisk in the cream until thick and creamy. Divide the chocolate filling evenly among the cooled tart shells and spread evenly. Bake for an additional 10 minutes until the filling is set.
Remove from the oven and let cool completely before serving.
Interesting Facts
Shortbread tarts are a traditional British treat.
The name “shortbread” comes from the fact that the pastry is made with a high ratio of butter to flour.
Chocolate is the perfect filling for these tarts, but you could also try other fillings such as jam, lemon curd or caramel.