Preheat your oven to 350 degrees and line your muffin tin with liners or grease them.
Make your flax egg ( 1 TB flax meal with 2 TB water) or egg replacer. Let this sit and thicken while you do the rest.
Grab your stand mixer and place your vegan butter ( you don't want this totally melted, just really soft, and it can be a little melty), oil, and sugars. Mix these until it's nice and combined. Add the vanilla, salt, flax egg, baking powder, and mix until incorporated. Now take your flour and vegan milk and mix until just mixed. Now stir in your chocolate chips. This batter is fairly thick.
Take a large cookie scoop and scoop the batter to the top of the muffin tin and repeat in the 12 slots.
Bake for 19-22 minutes. They will be done when a toothpick comes out mostly clean, don't overbake them. Let these cool in the pan for a few minutes, then on a cooling rack.
While the cupcakes are baking, you can make your frosting. Take your clean mixing bowl and add all the frosting ingredients. Mix with the whisk attachment for a minute or two until it's smooth; you may need to scrape down the sides.