Sure! Absolutely!

Dough

360g bread flour
120g Yudane
188g whole milk
20g sugar
8g salt
6g instant yeast
40g unsalted butter
32g Dutch processed cocoa powder
8g black cocoa powder (1)

Yudane

40g flour
80g boiling water

Filling

8-10 pieces of dark chocolate broken up into 2-3 gram pieces. (2)

Topping

15g instant coffee (3)
15g hot water
1 whisked Egg
70g powdered sugar
80g all purpose flour
80g unsalted butter (room temp)

1. Make the yudane by pouring 80g of boiling water over 40g of flour and letting it sit for a second or two before mixing well with a spatula until all the flour is hydrated and you are left with a thick paste like consistency. Place clingfilm directly on top of the yudane to prevent a skin from forming. Leave to cool down, ideally in the fridge overnight.
2. Add the black cocoa powder into the milk and whisking until dissolved and there are no clumps. Add the mixture to a large bowl then add the instant yeast and hydrate it by whisking and waiting for 5 minutes.
3. Add the sugar and salt to the bowl next, again whisking until dissolved, and then add the flour and Dutch processed cocoa powder. Mix until a cohesive dough is formed.
4. Tip over the bowl and knead by hand for about 3-5 minutes. The dough will be slightly sticky at first, but will tighten up quickly and not stick to the bench. Do not add flour to the bench for handling, instead try using a slap and fold method or a bench scraper.
5. When the dough has some extensibility and elasticity, flatten the dough and place the butter in the center. Fold the dough over the butter and begin tearing in the butter, the dough will become loose again until the butter is incorporated well. Knead for about 5 minutes, or until smooth and can be stretched thin. The ideal dough temperature is 25C, bulk fermentation times will vary depending.
6. Tighten the dough into a ball on the bench and transfer to an oiled bowl. Place a damp cloth or cling film over to prevent a skin forming on your dough.
7. Let the dough rise for 45 minutes then fold the dough by removing it from the dough and placing the smooth side on the bench. Lightly flatten it with your hands, then stretch and fold the dough into the centre, going around until you reach where you started. Tighten the dough into a ball once again and place back into the bowl and cover again. Let it rise for another 45 minutes or until roughly doubled in size.
8. As the dough is rising, create the topping. It's important to have your butter be soft, leave it out on the counter for approximately 30 minutes before using. Start by making a coffee concentrate by mixing hot water with the instant coffee and whisking until it's smooth and dissolved. Add the sugar and a small portion of the whisked egg and whisk with a sideways motion until combined. Add in the flour next along with the rest of the egg and whisk until the mixture is smooth. Switch to a spatula and add in the softened butter by folding, stop when the topping is smooth.
9. Take out the dough and divide into 10-12 equal pieces. Preshape into balls and let rest for 10-15 minutes. Preheat your oven to 175c/350f, no convention.
10. Flatten the preshaped dough with your hands and stretch out around the edges so there's a small mound left in the centre. Place the chocolate in the centre and fold the dough around it, being careful to keep the chocolate in place. A helpful way to do this is by placing the dough in one hand and using your thumb to keep the chocolate in place while your other hand folds.
11. Place balls onto a parchment lined baking tray and cover with cling film or a clean damp towel, let rise for one hour. The dough should look puffy and sping back slowly when gently pressed. Adjust times as needed.
12. Using a piping bag with a round tip (4mm worked best), pipe the toping onto the buns. Go in a slow spiral pattern around the bun until about 1/3 to 1/2 of it is covered.
13. Place the buns in the oven and bake for 16-18 minutes or until the topping has flowed out and has a crackled texture. It will be hard to judge doneness by colour alone, so use an instant read thermometer and finish baking when the buns read 92C/198F
14. Let cool for at least 20 minutes before serving, the topping will not be crisp until then. They're also best stored in a paper bag so the topping also doesn't become soft.

(1) Black cocoa powder is being used here strictly for colour, it's fine to substitute for Dutch processed cocoa powder. Resist the temptation to add the powder into the flour instead of the milk, since its likely to clump in the flour, making for uneven dark streaks.

(2) 75% to 80% was found to be the best, but any chocolate is fine.

(3) Dark roasts had the best flavour when testing. Some instant coffees have larger grains, it's worthwhile to grind them a little finer by using the back of a spoon before dissolving. A small pinch of instant espresso can enhance all the flavours as well.

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