Juvenile book about 2 maybe detective siblings?

This has been driving me crazy trying to remember for a long time!! I read this book (probably a series) maybe 5-10 years ago, so it's probably juvenile fiction. I am fairly certain it was about 2 siblings who traveled the country trying to either solve mysteries or track down a villain or both. There was one storyline where they ended up at House On The Rock in Wisconsin and were chased by the villain out into the Infinity Room and nearly falling through the floor into the forest below. There was another storyline where they were at an amusement park, possibly Hershey Park in Pennsylvania, and one of the siblings was trapped by the villain in a large glass container that was slowly filled with ice cream. The character experienced symptoms of hypothermia but was able to escape in the end.

Any help or ideas would be great! TIA!