Key Lime Cupcakes

I find it to be very delicious. However, I realize the lime curd has a lot of cornstarch... (and honestly, it was still a little on the runny side for me.. I'd add a bit more) but it tastes good! I've never used agar agar, but you have and you think it would work better for this, try it and let me know how it goes please!

Cupcake batter
1/2 c. Earth Balance butter
3/4 c. sugar
1 1/2 c. flour
3 Ener-G Egg Replacers (equiv. of 3 eggs - in powder form)
1 1/2 t. baking powder
1/2 t. baking soda
1 c. milk substitute
Zest and juice of 1 large lime
1/4 t. sea salt

Directions:
Beat Earthy B and sugar until creamy. Then add all dry ingredients, lime juice/zest and milk - combine until smooth. Scoop into cupcake pan and bake at 350 degrees for 23-25 minutes. Let cool. (This should make 12 cupcakes) After cool, fill the center of each cupcake with lime curd by using a knife to cut a hole in the middle that does NOT go through to the bottom. After it's filled, put the cut out piece back on top. Ice with lime icing. Enjoy!

Lime Curd
1/4 c. cornstarch, plus extra to make thicker (use your judgement)
1/3 c. lime juice
1 T. lime zest
3/4 c. sugar
4 T. Earthy B
3 T. milk substitute

Directions:
In a small pan, combine sugar, lime juice and zest, milk substitute and Earthy B. Cook until sugar is dissolved, then add cornstarch and cook until thickened. Remove from heat and allow to cool.

Lime Icing:
1/2 c. Earthy B
3 c. powdered sugar
1 t. lime zest
1 T. lime juice

Directions:
In a bowl, beat butter until creamy. Add sugar, lime juice, and lime zest and stir until combined.