The proposed study will test the usability and feasibility of a novel cognitive training (COGMUSE) for autistic adults with co-occurring insomnia (COGMUSE- AUT). Participants (n=15) will complete the cognitive training intervention for 60 minutes per day, 3 times per week for 6 weeks at home totaling to 18 hours. Weekly check-ins will be conducted by study staff over Teams to ensure adherence to the treatment and provide an opportunity for qualitative feedback on the game sessions played. During these 6 weeks, participants will fill out daily (2x/day) electronic sleep diaries and wear an actigraph device (GENEActiv). GENEActiv is a watch-like device that monitors light and movement activity.

Inclusion Criteria:

1. 18+ years of age
2. Diagnosed with ASD (see 2a).
3. Verbal IQ >= 70 (Measured via the Weschler Abbreviated Scale of Intelligence 2nd Edition28); to ensure verbal skills sufficient to participate in treatment
4. Able to undergo actigraphy assessment
5. Can read and understand English
6. Diagnosed with insomnia (See 3a).
7. No prescribed or OTC sleep medications for 1+ month, or stabilized on medications for 6+ weeks.

2a) ASDb: a) previous DSM diagnosis of ASD (self-reported by ASD adult and guardian; confirmed by clinical documentation provided to project coordinator), 2) evaluation using gold-standard diagnostic tools (i.e., Autism Diagnostic Observation Schedule (ADOS) and/or Autism Diagnostic Interview -Revised [ADI-R]).

3a) Insomnia: a) insomnia complaints for 6+ months that b) occur despite adequate opportunity and circumstances for sleep, c) consist of 1 or more of the following: difficulty falling asleep, staying asleep, or waking up too early, d) daytime dysfunction (mood, cognitive, social, occupational) due to insomnia, f) baseline diaries and actigraphy indicate >30 minutes of sleep onset latency or wake after sleep onset on 6 or more nights.

Exclusion Criteria:

1. unable to provide informed consent
2. diagnosis of sleep disorder other than insomnia [i.e., sleep apnea (apnea/hypopnea index, AHI >15), Periodic Limb Movement Disorder (myoclonus arousals per hour >15)],
3. comorbid bipolar or seizure disorder (due to risk of sleep restriction treatment)
4. other major psychopathology except depression or anxiety (e.g., suicidal ideation/intent, psychotic disorders)
5. severe untreated psychiatric comorbidity
6. psychotropic or other medications (e.g., beta-blockers) that alter sleep
7. participation in non-pharmacological treatment (including CBT) for pain, sleep or mood outside current trial.