Preheat oven to 180°C. Grease and line a 20x20 cm (approx.) tin.
Mix the hot water and cocoa powder until you get a smooth paste. Set it aside to cool.
Pit and halve the cherries, then put them on a plate, lined with kitchen paper towels.
In a large mixing bowl, combine the flour, sugar, baking powder and salt.
In another bowl, lightly whisk the eggs, then add the oil, vanilla extract, and the cocoa paste.
Add egg mixture to the flour mixture and gently combine. Don’t overmix the batter!
Toss the cherries with the 1 Tbsp of flour (this will prevent them from sinking during baking).
Fold the cherries and chocolate chips into the batter, then transfer the mixture to the prepared pan, spreading it out evenly.
Bake for 35-40 minutes in the middle of the oven. Test the middle of the cake with an inserted toothpick - if it comes out clean, it’s ready. If it’s wet, bake for a further 5-10 minutes and test again.
Let the cake cool in the tin for 5 minutes, then transfer it to a wire rack.
Let it cool completely, then dust with icing sugar just before serving.