Preheat a fan-forced oven to 160C (320F) or 180C (356F) for a conventional oven. Line a cupcake tin with cupcake liners.
In the bowl of a stand mixer fitted with the paddle attachment, add the flour, earl grey tea leaf powder, baking powder, caster sugar and salt. Turn mixer on low speed and allow it to mix for a couple minutes to help everything combine well (alternatively you may do this by sifting the ingredients together). Add the softened butter and let it mix until it resembles a fine sand like texture.
Next, add milk, eggs, yogurt, oil and vanilla extract in a large jug and whisk well.
Add wet ingredients to dry ingredients along with food gel colouring. Scrape down the bowl and mix for another 20 seconds to make sure batter colours and mixes evenly.
Fill each paper 3/4 of the way (using an ice cream scoop to transfer the batter into the cupcake liners makes this a quick and easy process otherwise you can use two tablespoons). Bake for 30 min or until a toothpick inserted comes out clean. Allow them to cool completely on a wire cooling rack before frosting.
To prepare frosting add earl grey tea and food gels and mix until well combined and evenly coloured.
Fit the end of a piping bag with a Wilton 8B piping tip and frost a swirl of frosting on top.
To prepare the gold splatter add gold lustre dust and vodka or water to a small mixing bowl and mix until well combined. Use a new tooth brush or teaspoon to splatter the gold onto the frosting.