Here's something I hacked together from some code I borrowed from an npm package called Number to Words, so most of the credit goes there. I just added a little logic to make it work for currency. You'll want to thoroughly test this due to the duct tape and baling wire nature of the code.

You just need to call the function toWords and pass it a number.

var TEN = 10;
var ONE_HUNDRED = 100;
var ONE_THOUSAND = 1000;
var ONE_MILLION = 1000000;
var ONE_BILLION = 1000000000;           //         1.000.000.000 (9)
var ONE_TRILLION = 1000000000000;       //     1.000.000.000.000 (12)
var ONE_QUADRILLION = 1000000000000000; // 1.000.000.000.000.000 (15)
var MAX = 9007199254740992;             // 9.007.199.254.740.992 (15)

var LESS_THAN_TWENTY = [
    'Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten',
    'Eleven', 'Twelve', 'Thirteen', 'Fourteen', 'Fifteen', 'Sixteen', 'Seventeen', 'Eighteen', 'Nineteen'
];

var TENTHS_LESS_THAN_HUNDRED = [
    'Zero', 'Ten', 'Twenty', 'Thirty', 'Forty', 'Fifty', 'Sixty', 'Seventy', 'Eighty', 'Ninety'
];

function isSafeNumber(value) {
    return typeof value === 'number' && Math.abs(value) < MAX;
}

function isFinite(value) {
    return !(typeof value !== 'number' || value !== value || value === Infinity || value === -Infinity);
}

function toWords(number) {
    var words;

    if (!isFinite(number)) {
        throw new TypeError(
            'Not a finite number: ' + number + ' (' + typeof number + ')'
        );
    }
    if (!isSafeNumber(number)) {
        throw new RangeError(
            'Input is not a safe number, it’s either too large or too small.'
        );
    }

    // Begin custom currency logic
    let whole = Math.floor(number);
    let fraction = (number % 1).toFixed(2) * 100
    let wholeWords = generateWords(whole);
    let fractionWords = generateWords(fraction);

    let pesewa = '';
    
    if(whole == 1){
        pesewa = " Pesewa";
    } else {
        pesewa = " Pesewas";
    }

    let cedi = '';

    if(fraction == 1){
        cedi = " Cedi";
    } else {
        cedi = " Cedis";
    }

    words = generateWords(whole) + pesewa + ' and ' + generateWords(fraction) + cedi;
    return words;
}

function generateWords(number) {
    var remainder, word,
        words = arguments[1];

    // We’re done
    if (number === 0) {
        return !words ? 'Zero' : words.join(' ').replace(/,$/, '');
    }
    // First run
    if (!words) {
        words = [];
    }
    // If negative, prepend “minus”
    if (number < 0) {
        words.push('minus');
        number = Math.abs(number);
    }

    if (number < 20) {
        remainder = 0;
        word = LESS_THAN_TWENTY[number];

    } else if (number < ONE_HUNDRED) {
        remainder = number % TEN;
        word = TENTHS_LESS_THAN_HUNDRED[Math.floor(number / TEN)];
        // In case of remainder, we need to handle it here to be able to add the “-”
        if (remainder) {
            word += '-' + LESS_THAN_TWENTY[remainder];
            remainder = 0;
        }

    } else if (number < ONE_THOUSAND) {
        remainder = number % ONE_HUNDRED;
        word = generateWords(Math.floor(number / ONE_HUNDRED)) + ' hundred';

    } else if (number < ONE_MILLION) {
        remainder = number % ONE_THOUSAND;
        word = generateWords(Math.floor(number / ONE_THOUSAND)) + ' thousand,';

    } else if (number < ONE_BILLION) {
        remainder = number % ONE_MILLION;
        word = generateWords(Math.floor(number / ONE_MILLION)) + ' million,';

    } else if (number < ONE_TRILLION) {
        remainder = number % ONE_BILLION;
        word = generateWords(Math.floor(number / ONE_BILLION)) + ' billion,';

    } else if (number < ONE_QUADRILLION) {
        remainder = number % ONE_TRILLION;
        word = generateWords(Math.floor(number / ONE_TRILLION)) + ' trillion,';

    } else if (number <= MAX) {
        remainder = number % ONE_QUADRILLION;
        word = generateWords(Math.floor(number / ONE_QUADRILLION)) +
        ' quadrillion,';
    }

    words.push(word);
    return generateWords(remainder, words);
}