Instant and rolled are not the same.
From less processed to most processed you have:
- oat groats ... look like rice kernels and take the longest to cook (most of an hour)
- steel-cut oats ... 1/2 to 1/3 the size of groats, because they are sliced up (steel cut!) groats, take less time (~25 minutes) to cook
- rolled or *traditional* oats ... groats that are steamed and rolled flat; at Walmart they're in the cannister with the *blue* ribbon and take about 15 or so minutes of simmering to cook
- *quick* oats are rolled oats that are cut up a bit and rolled thinner, so they cook within about 5 minutes (they may be the reddish cannister)
- *instant* oats are precooked and soft, and cook within a minute ... or just add boiling water and stir.
In baking rolled and quick oats are *mostly* interchangeable. Instant oats are not.