Cardboard boxes - we've played in them, made them into castles, decorated them...for whatever reason, it keeps them entertained forever. In the picture above (taken first week of January, that's why my tree is up :), we made it into a train and I pushed them around the room. Nice exercise for mom! ;)
Cooking - Abby is obsessed with cooking and baking. We've been stocking up our freezer with meals, cookie dough, and muffins/breads. Her favorite request: brownies ... I can't complain! :) She also likes putting on her apron and washing the dishes afterward. Just make a nice bubble bath for the dishes, give the girl a sponge, and she's a happy camper for awhile. :)
I cut different shapes into boxes and had her sort items through the holes. Then she got to decorate the box with stickers. :)
Blanket forts - we have been making lots of forts with old sheets. We do puzzles, color pictures, and read all the time, so it's a nice change of scenery inside the forts. Plus, Tim finds it hilarious to rip down so he can watch us rebuild it! ;)
Messy play - we've made play dough and cloud dough (pictured above). Cloud dough was insanely messy, but Abby loved it. It is really easy to make - 1/4 cup of vegetable oil and 2 cups of flour. Mix together and enjoy!! I like how it's made from food, so if your little one wants a sample (because you know they will!), it's safe to eat! :)
Any other fun ideas for indoor play? What are you doing to keep sane this winter?