Failing to "Create New Complex Type" when promoting Stored procedure to Function in EF

Stored procedure having temporary table declaration needs to be replaced with  TABLE variable declaration.

e.g.

CREATE Procedure spDoSomethingAmazing
AS
BEGIN
CREATE TABLE #Temp (ID INT, Name VARCHAR(50)

INSERT INTO #Temp
SELECT
ID, Name
FROM
TestTable

SELECT ID, Name #Temp

DROP TABLE #Temp
END

-- Modified version of Stored procedure so Entity Framework can generate Complex Type

CREATE Procedure spDoSomethingAmazingForEF
AS

BEGIN
DECLARE @Temp TABLE (ID INT, Name VARCHAR(50)

INSERT INTO @Temp
SELECT
ID, Name
FROM
TestTable

SELECT ID, Name @Temp

END