Inclusion Criteria:  History of immunoglobulin E (IgE)-mediated food allergy to peanut or tree nut Positive skin prick test to the trigger food (either peanut or tree nut) Objective clinical reaction to the food allergen during baseline oral food challenge Women of child bearing potential must agree to two forms of highly effective contraception (hormonal, device, or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 7 days following completion of acalabrutinib therapy. Ability to understand and the willingness to sign a written informed consent Ability to clearly understand and speak English at an 8th grade reading level  Exclusion Criteria:  Participants who have been on immunomodulatory therapies or oral corticosteroids within 1 month prior to enrollment Participants with symptoms consistent with food reactions other than type 1 hypersensitivity History of allergic reaction to acalabrutinib History of idiopathic urticaria, dermatographism, idiopathic or unexplained anaphylaxis, or anaphylaxis (to foods or otherwise) resulting in intubation, prolonged hypotension, or neurological sequelae- History of cardiovascular disease History of a bleeding disorder, or those currently taking blood thinners History of stroke History of gastrointestinal ulcer History of cancer (other than skin cancer) Positive HIV status or history of other immunodeficiency Active or latent Hepatitis B or C infection based on laboratory testing Currently pregnant or nursing Current use of proton pump inhibitors (Note: participants currently receiving proton pump inhibitors who switch to H2-receptor antagonists or other antacids are eligible for enrollment to this study). Active significant infection Major surgical procedure within 28 days of enrollment Uncontrolled autoimmune hemolytic anemia or idiopathic thrombocytopenic purpura Difficulty swallowing oral medication, or significant gastrointestinal disease that would limit absorption of oral medication Concurrent participation in another therapeutic clinical trial