Cube the butter small, (about 1cm or ⅓” ) to soften and come to room temperature quicker.
Sieve the 292 grams Plain Flour & 3 tsp Baking Powder into a medium mixing bowl. Add the ¾ tsp Salt, 1 tsp Smoked Paprika, 1¼ tsp Mustard Powder, Pinch of Garlic Pepper, 1 tsp Dried Rosemary &1 tsp Dried Parsley & whisk together. **For UK Self-raising flour, omit the baking powder.
Pre-heat your oven to: 190°c/170°c fan oven/ 375°f/Gas mark 5.
Add the softened 83 grams Unsalted Butter, 3 Medium Eggs & 180 ml Milk to a large mixing bowl or stand mixer & mix together. Start on low, progressing up to high for at least 15 seconds. Beat until bubbles & foam forms. **Note the butter might look a little strange & not combine fully at this point, but will be fine.
Add the flour/seasoning mixture & briefly mix by hand. Then use the mixer to bring together into a smooth but thick batter. See video. Fold in the cheddar cheese cubes in 2 batches.
Line a 12-hole cupcake tray with 12 paper muffin cases. Then add about 1 heaped tablespoon worth of the batter into the bottom of each case. Place 2 cubes of the 76 grams Mozzarella on top of the batter, into the centre. Alternatively, for grated/shredded mozzarella, take about 1 tablespoon worth & mould into a rough ball/oval shape. Gently push down into the centre of the batter. Then cover the top with the remaining batter. *The cases will be about 85% full. Sprinkle dried parsley on top & tap the cupcake tray on the counter/worktop a few times before popping in the oven to bake.