Preheat oven to 425 and line 24 standard cupcake/muffin cups with cupcake liners.
In a large mixing bowl, add the lemon juice to the milk and let sit for 2-3 minutes.
Whisk in the oil, eggs and vanilla.
Add the brown sugar, granulated sugar and hot water and whisk until well combined.
Sift in the flour, cocoa powder, baking powder and salt, then whisk until combined.
Stir in the chocolate chips. (Optional stir in only 1-1/2 cups of the chocolate chips then press the remaining chocolate chips in to the muffin tops before baking.)
Fill your muffin cups just about to the top. (Optional: Sprinkle a few chocolate chips on the top of each one.)
Bake at 425 for 5 minutes, lower the temperature on the oven to 350, (don’t open the door), and let bake another 15-17 minutes.
Remove from the oven. Let the muffins cool in the muffin/cupcake pan for 5-10 minutes then remove and place on cooling racks. Once they are cooled they are ready to serve!