Lightly grease your microwave safe mugs.
In a medium bowl, whisk together the egg, cream, molasses sugar and vanilla extract, then whisk in the slightly cooled melted butter.
2 tablespoons butter, 1 egg, 3 tablespoons molasses sugar, 1 tablespoon double cream, ½ teaspoon vanilla extract
In a separate bowl mix together the flour, baking powder and salt.
8 tablespoons all purpose flour, ½ teaspoon baking powder, pinch sea salt
Stir the dry ingredients into the wet ingredients until just combined and then fold through the dates.
2 medjool dates
Divide the batter between the two prepared mugs.
Gently mix together the cream, sugar and salt for the sauce (see notes) and pour on top the cake mix in each mug, spread out if necessary. You'll need to make this mixture twice - once for each mug.
2 tablespoons double cream, 2 tablespoons dark brown sugar, pinch sea salt
Microwave each mug for 1 minute 20 seconds until risen and saucy on top.