The wonderful thing about mochi is that you can put anything inside. If you need some inspiration you can go with chocolate ganache, ice cream, fruits, peanut butter, crushed cookies, jam, sweet bean/seed pastes, and even savory things. The only caveat is that you probably want whatever you are making to look good, so I would stick to foods that you know will keep the shape you want.
Red Bean Paste and Black Sesame Paste – you can get right out of a can (or make it yourself)
Sesame Peanut Butter – I didn’t have sesame paste in my house so I crushed sesame by hand with a mortar pestle and mixed it with peanut butter. I used about equal parts of both because I didn’t want a very sweet mochi (with too much peanut butter), and when you use more sesame it keeps it’s shape better.
Chocolate Ganache AKA Chocolate Truffles- It’s pretty straightforward to make a simple chocolate truffle; it is so simple that you’ll possibly not buy one ever again. You have two basic ingredients: chocolate and milk.
After a lot of experimentation, reading, and 10 hours later, I’ve figured out my favorite mochi recipe. I knew from the start I wanted to use the microwave if possible (I had a bad experience with steam) and that I was okay with missing out on all the traditional fun of pounding glutinous rice. What you need for my favorite recipe of (lucky) 8 daifukus: 1 cup glutinous rice flour ¼ c granulated sugar ¼ tsp salt 1.25 cup room temp water (or 1 cup water, 1/4 cup coconut milk) Optional: desiccated coconut, fillings (peanut butter, sesame seeds, red bean paste, sesame paste, whatever your heart desires) Combine your dry ingredients, then add 50% of the water. Stir until you’ve made a consistent dough, then mix in the rest of the water (you do this whenever mixing dry and wet ingredients to prevent lumps of flour in your mixture). The consistency was much more watery than I expected. If you want to add food coloring, I’d also put in two drops into the watery mixture. Prep a surface (counter, cutting board, etc) with a layer of corn starch. Microwave your mixture for two minutes, stir until consistent, then microwave again for 3 minutes. Pour the dough onto parchment paper or surface covered in corn starch. It should look like this (sans food coloring):Divide what you have evenly into 8 pieces, shape into flat disks with thicker middles and thinner edges. Place your filling right into the center (I recommend a disk instead of a ball since because your final shape isn’t going to be perfectly round), then seal by pinching all the edges to the center. Cover your final product with corn starch, and for final presentation brush off the remaining cornstarch. The ones on the left have four drops of food coloring (I recommend only two), and the ones on the left have no food coloring: This is two drops of food coloring:
Recipe adjustments: I add some coconut milk in place of water for a slightly richer flavor. It is pretty subtle, but if you are going to use more coconut milk you need to add more water, unless you want a chewier texture. It also makes the mochi harder to work with when you are shaping. My Dad is a big fan of the super chewy mochi so he doesn’t like my variation, but you can also achieve a chewier texture with lowering water content/upping dry mix and/or steaming your mochi instead. HAVE FUN!